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HomeMy WebLinkAbout; Alta Mira & Zone 19 Park Biological Report; Alta Mira & Zone 19 Park Biological Report; 1992-01-31BIOLOGICAL RESOURCES TECHNICAL REPORT FOR THE ALTA MIRA AND ZONE 19 PARKS IN THE CITY OF CARLSBAD Prepared for: City of Carlsbad 2075 Las Pal mas Drive Carlsbad, CA 92009-4859 Attention: Mr. Pat Entezari Prepared by: P&D TECHNOLOGIES 401 West A Street, Suite 2500 San Diego, CA 92101 Attention: Ms. Elyssa Robertson January 31,1992 TABLE OF CONTENTS Section Page INTRODUCTION 1 Soils 4 SURVEY METHODS AND LIMITATIONS 5 EXISTING CONDITIONS 5 Vegetation/Habitats 5 Special Interest Plants and Habitats 10 Wildlife 13 Special Interest Wildlife Species 16 IMPACTS/CONSTRAINTS 20 MITIGATION RECOMMENDATIONS 21 LITERATURE CITED 24 LIST OF TABLES Table Number Title page 1 Soils 4 2 Special Interest Plants Species 11 3 Special Interest Wildlife Species 17 LIST OF FIGURES Figure Number 1 2 3 4 Title Regional Map Vicinity Map Biological Resources of Alta Mira Park Biological Resources of Zone 19 Park Page 2 3 6 9 ATTACHMENTS Number A B C Title Floral Species List Faunal Species List California Native Plant Society Listing and Sensitivity - Federal Candidate Species Designations 11 INTRODUCTION The Alta Mira and Zone 19 park project sites were surveyed by P&D Technologies biological resource team. The purpose of the biological assessment was to provide the City of Carlsbad with a planning document which would enable the City to avoid, to the maximum extent feasible, potentially significant effects to the site's special interest species and habitats. These proposed park projects are part of the Carlsbad Parks Master Plan and are planned as active recreational parks. Park design has not been completed; therefore, this report represents a constraints level of analysis. This biological report addresses the presence or absence of significant biological resources onsite and the degree to which the proposed parks may affect such resources, if any. Significant biological resources are defined herein as any plant or animal species listed as rare, threatened, or endangered by State or Federal resource agencies, or is considered a depleted or declining species, and/or any species or natural plant communities (habitat) considered as limited in distribution or such habitat which typically supports special interest species. The proposed park sites are generally located in north-coastal San Diego County in the City of Carlsbad and are bounded by Palomar Airport Road to the north, Batiqiritos Lagoon to the south, El Camino Real to the east, and Interstate 5 to the west (figures 1 and 2). More specifically, the proposed Alta Mira park is situated immediately east of and adjacent to Paseo Del Norte Road in the southern portion of the City of Carlsbad. It occupies approximately 42 acres of primarily native habitat and lands in various stages of agricultural production. The site is situated on top of the hills above and south of Canyon de las Encinas and is surrounded by on-going urban development activity. The proposed Zone 19 park is located south of the intersection of Palomar Airport Road and Camino Vida Roble and occupies approximately 35 acres on the hills above and south of Encinas Creek Canyon. The proposed Zone 19 park project site occupies lands predominantly disturbed by agricultural production, although portions of the project site extend out onto a small mesa-like Camp Pendieton Riverside County O'NxffUMi> PROJECT SITE AREAL Oceanside | Valley Center LJ*t Wofiltora San Marcos «M«/VO» / j?*^ ^3 Afut Ht&onat ' UfOOII Carlsbad Wpp * Ltgooo t Encinitu \ Sin Ou«iwo Rancho Santa Fe t.a*t A«mon«Rancho ,* Bernardo tf Del Mira Mesa Ll JOIH •10'I San Diego i Chula Vista Imperial Beach n/uj<n fjrujo-1 4 F No Scale Regional Map Figure 2 Scale: r> 2000' Source: Base Map. 2000* Encinitas Quadrangle 1975.Project Location along the western margin of the site. Lands immediately to the south, east, and west are currently proposed for residential development as part of the Aviara development project SOILS Eight soil types have been mapped by the U.S. Department of Agriculture (USDA), Soil Conservation Service (SCS), for the proposed Alta Mira and Zone 19 park project areas. These soils are listed and described in Table 1. TABLE 1 SOIL TYPES IDENTIFIED FOR ALTA MIRA AND ZONE 19 PARK SITES PROJECT SOIL TYPE DESCRIPTION/CHARACTERISTICS Alta Mira TeF Terrace escarpments; severe limitations for conversion from brush to grass; severe credibility potential; Group D hydrologic soils. LeE Las Flores loamy fine sand; 15-30% slopes; slight limitations for conversion from brush to grass; severe credibility potential; Group D hydrologic soils. MIC Marina loamy coarse sand; 2-9% slopes; slight limitation for conversion from brush to grass; severe credibility potential; Group A hydrologic soils. CfC Chesterton fine sandy loam; 5-9% slopes; slight limitations for conversion from brush to grass; severe credibility potential; Group D hydrologic soils. CfB Chesterton fine sandy loam; 2-5% slopes; slight limitations for conversion from brush to grass; severe credibility potential; Group D hydrologic soils. ScA Salinas clay, 0-2% slopes; slight limitations for conversion frombrush to grass; slight credibility potential; Group C hydrologic soils. Zone 19 LvF3 Loamy alluvial land, Huerhuero complex; 9-50% slopes; severe limitations for conversion from brush to grass; severe credibility potential; Group D hydrologic soils. RdC Redding gravelly loam; 2-9% slopes; moderate limitations for conversion from brush to grass; severe credibility potential; Group D hydrologic soils. CfB Chesterton fine sandy loam; 2-5% slopes; slight limitations for conversion from brush to grass; severe credibility potential; Group D hydrologic soils. ScA Salinas clay; 0-2% slopes; slight limitations for conversion frombrush to grass; slight credibility potential; Group C hydrologic soils. SURVEY METHODS AND LIMITATIONS Both project sites were surveyed on foot by P&D Technologies biologist Ray Vizgirdas on December 31, 1991 between the hours of 0800 and 1400. All native habitats were visited, and all observed plants were identified. Animals were identified by their sign, including scat, tracks, burrows, and vocalizations or by direct observation. Where particularly dense vegetation or steep topographic relief was encountered, observations were made using binoculars. The primary focus of the survey was to map all habitats and sensitive resources. Mapping was conducted on orthotopographic maps at a 1 inch = 100 feet scale. No detailed plant transects or animal trapping studies were conducted as part of this effort Further limitations to the completeness of the faunal and floral inventory were imposed by seasonal and/or temporal factors. Plants observed were identified and inventoried in the field or on the basis of characteristic samples returned to P&D's offices. Nomenclature used throughout this report conforms to Munz (1974) for plants, Holland (1986) for vegetative communities, AOU (1983) for birds, Jennings (1983) for reptiles and amphibians, and Jones (1982) for mammals. EXISTING CONDITIONS The information presented below has been divided into two sub-sections and describes each park site separately. This has been done to allow for ease of use when referencing the potential biological effects of each park site. VEGETATION/HABITATS Alta Mira Park Four plant communities are represented onsite: riparian scrub, Diegan coastal sage scrub, floodplain (unvegetated, sandy wash), and disturbed vegetation (agricultural fields) (Figure 3). A complete floral species list is included as Attachment A of this report r. ^ Scale: 1"=167 Figure 3 Source: 100' Scale City of Carlsbad Orthophoto Map. 1988 BEST ORIGINAL A|ta Mjra parR Bjo(ogjca| Reso(jrces ''"""^ The riparian scrub habitat onsite occupies approximately 0.5 acres within the two acre floodplain i^^located along the western margin of the site. This floodplain is located between coastal sage scrub to the west and agricultural fields to the east This riparian scrub habitat is poorly developed, and no well defined stream bank exists. Riparian scrub is a class of wetland vegetation dominated by woody vegetation less than six meters (20 feet) in height Typical species in this class are considered true shrubs, young trees, and trees or shrubs that are small or stunted due to environmental conditions (wet soils). In drainages where available water depends on seasonal and urban runoff, an open riparian scrub community of wash-associated shrubs occurs. Two small patches of willows (Salix sp.) and one small patch of mulefat scrub represent the dominant riparian scrub plant species onsite. This riparian scrub habitat exists as isolated pockets of vegetation which have been disturbed to some degree by surrounding development and adjacent agricultural activities. Though the willows are large and usually offer excellent habitat, the small size of these habitats onsite, as well as their isolated nature, diminishes their overall value to wildlife species. This riparian scrub habitat ,^8»SRV .^ appears to be supported by intermittent water flow from surrounding development and from agricultural runoff to this shallow drainage. The floodplain area consists predominantly of numerous common weedy species such as cocklebur Qtanthium strumarium), Russian thistle (Salsola ibericd), mustard (Brassica sp.), star thistle (Centaurea melitensis) and tree tobacco Qficotiana glaucd). This habitat is considered disturbed and, if left alone, would regenerate to riparian scrub habitat The Diegan coastal sage scrub habitat represented onsite consists of approximately 8.5 acres and is composed primarily of low, soft, woody subshrubs forming a nearly uniform height to approximately three-to-four feet Many of these plants are facultatively drought deciduous. This association is typically found on dry sites, such as steep, south and southeast-facing slopes or on clay-rich soils that are slow to release stored water. The dominant shrub species observed onsite include: California sagebrush (Artemisia californicd), chamise (Adenostomafasciculatwri), flat- topped buckwheat (Eriogonwn fasciculatum), broom baccharis (Baccharis sarothroides), and black sage (Salvia melliferd). The quality of this habitat type onsite is relatively high, exhibiting minimal disturbance. The remainder of this site probably supported similar native vegetation prior to the current agricultural activities. The bulk of lands onsite have been heavily disturbed by on-going agricultural activities and dirt access roads, and consist of approximately 30.5 acres. Disturbed areas of the project site are dominated by weedy, introduced species, and plant cover is generally open due to frequent and/or recent disturbance. Common species here include red-stem filaree (Erodium cicutariwn), fennel (Foeniculum vulgare), Russian thistle, bull thistle (Cirsium vulgare), telegraph weed (Heterotheca grandiflora), and flower crop species. Approximately one acre of chaparral vegetation exists as a small, isolated patch in the northwestern corner of the park site. Plant species which dominate this habitat consist of chamise, scattered laurel sumac (Malosma laurina), California buckwheat (Eriogomun fasciculatwri), and black sage. Zone 19 Park Two plant communities are represented onsite: chaparral and disturbed vegetation in the form of agricultural fields (Figure 4). A complete floral species list is included as Attachment A of this report Although a majority of the site is dominated by historic agricultural activity, the northern and western portion of the site encompass slopes of an adjacent canyon which contain chaparral vegetation. This mixed chaparral community consists of approximately 10 acres and is dominated by lemonade berry (Rhus integrefolia), laurel sumac, toyon (Heteromeles arbutifolid), mission manzanita (Xylococcus bicolor), black sage, chamise, California buckwheat, and scattered oak trees (Quercus agrifolia). Two large, specimen size coast live oak trees (Quercus agrifolia) exist on the more level portions in the northeast corner of the site. In general, agriculture and/or disturbed areas dominate the project site. Typical weedy, introduced species similar to those present in non-native grassland habitats were observed here, 8 o o u BEST ORIGIN/, F ^ Scale: 1"=167' Figure 4 Source: 100' Scale City of Carlsbad Orthophoto Map. 1988 Zone 19 Park Biological Resources || v, although plant cover is generally less evident due to frequent and/or recent disturbance. Common species here include red-stem filaree, fennel, Russian thistle, and telegraph weed. The lands onsite that have been heavily disturbed by historic agricultural activities and creation of dirt access roads consist of approximately 25 acres. SPECIAL INTEREST PLANTS AND HABITATS Alta Mira Park Special interest plant species and habitats are those which are considered rare within the region, have been identified by the California Natural Diversity Data Base, or support plants or animals considered sensitive by resource protection agencies (U.S. Fish and Wildlife Service and the California Department of Fish and Game). Special interest plants and habitats are so called because of their limited distribution, restricted habitat requirements, or particular susceptibility to human disturbance, or a combination of these factors. Sources used for the determination of sensitive biological resources include: U.S. Fish and Wildlife Service (USFWS, 1985 {a and b}), California Department of Fish and Game (CDFG, 1987), and California Native Plant Society (Smith, 1988). Table 2 lists the sensitive plant species known from the project area, legal status, and the habitat in which they are generally found. These species were not observed onsite and are not expected to occur onsite due to inappropriate habitat and soil conditions. The special interest habitats onsite include riparian scrub and Diegan coastal sage scrub associations. Riparian habitats, in general, are considered a particularly sensitive resource by the California Department of Fish and Game. This habitat type is defined as a wetland by the U.S. Fish and Wildlife Service (Cowardin eL al, 1979). Wetland habitat is specifically addressed by the California Department of Fish and Game Code sections 1600-1606 (Streambed Alteration Agreement). Wetlands may also fall under the jurisdiction of the U.S. Army Corps of Engineers, Section 404 permit process. Wetland habitat is also considered a valuable but declining resource locally. 10 TABLE 2 SPECIAL INTEREST PLANT SPECIES KNOWN FROM THE PROJECT AREA SPECIES Acanlhamintha ilicifolia San Diego thommint Adolphia californica California adolphia Baccharis vanessae Encinitas baccharis Ceanothus verrucosus Warty-stemmed ceanotbus Corethrogyne filaginifolia CNPS IB 2 IB 2 IB STATUS Red Code CDFG USFWS 2-3-2 CE C2 1-2-1 2-3-3 CE C2 1-2-1 3-2-3 - C2 HABITAT chap/css/grs/clay chap chap chap chap var. UnifoUa Del Mar Mesa sand aster Harpogonella palmeri var. palmeri Palmer's grappling-hook 1-2-1 chap/css/grs chap = chaparral grs = grassland ess = coastal sage scrub clay = clay soils Source: Refer to Appendix C for an explanation of the status designation Under Section 404 of the Clean Water Act, wetlands are subject to permit provisions regulating activities within their boundaries. These are enforced by the U.S. Army Corps of Engineers and the U.S. Environmental Protection Agency, with technical input from the U.S. Fish and Wildlife Service. Wetland habitat is naturally limited and remaining acreages are important islands for migrant birds. Many bird species are restricted to riparian habitat and are dependent on it for breeding. Overall wildlife diversity is normally substantially higher in riparian areas than in surrounding habitats. Such habitats, by occupying natural drainages, also function to control water quality and erosion, as well as serve as wildlife corridors. 11 Three factors are considered in the designation of wetlands: the presence of hydrophytic vegetation, hydric soils, and site hydrology. A minimum of one positive wetland indicator from each category must be found for the Corps to determine an area to be a wetland (U.S. Army Corps of Engineers, 1986). Areas indicated as wetlands by all three factors during the rainy season may lack the indicators of hydrology and/or vegetation during the dry season, or the vegetation may have been altered or removed through human disturbance. Such areas may still be regarded as wetlands by resource agencies. Wetlands on the project site include southern riparian scrub totalling approximately 0.6 acres. Coastal sage scrub is considered a sensitive habitat by the County of San Diego. Atwood (1990) has estimated that as much as 80 percent of the original acreage of this habitat in the State has been lost as a result of urban expansion in coastal areas. Attwood (1990) has called coastal sage scrub one of the most endangered habitats in the nation. Additional evidence of the decline of this once common habitat is the growing number of declining plant and animal species associated with it The proposed Alta Mira project site contains approximately 8.5 acres of high quality Diegan coastal sage scrub. Zone 19 Park No special interest plant species were observed onsite during the surveys and none are expected due to the amount of disturbance. However, the onsite oak trees are considered an important resource by state and federal agencies, as well as the City of Carlsbad and the County of San Diego. As an integral component of the chaparral habitat onsite, the coast live oak trees are scattered among the slopes of the onsite canyons. Two large oak trees also exist near the northeast corner of the site, where a small draw enters the project area from the north. These oaks, though numerous, are scattered in such a way that they do not constitute a forest or woodland habitat, in and of themselves. These tree, however, do offer opportunities for perching, roosting, and nesting for a variety of raptor species. 12 WILDLIFE Alta Mira Park Due to the sparsity of native vegetation and a predominance of disturbed areas onsite, wildlife is expected to consist of a limited representation of what normally would be expected in the coastal foothills and valley grassland regions of San Diego County. The open character of much of the site should attract a variety of raptors; however, wildlife species would not be especially attracted to the riparian scrub areas onsite due to their limited size and isolated nature (not contiguous with similar habitat). Species either observed or indicated by direct evidence are listed in attachments B and C of this report Wildlife species considered of high interest are discussed within the text of this report. A relatively small number of reptile and mammal species were actually observed during the field reconnaissance. This is due, in part, to a variety of factors including time of year and the nocturnal and secretive habits of many species which may occur in the area. The observed and expected fauna of the project site are discussed by taxonomic grouping below. Amphibians - Though no amphibians were detected during the project survey, several species could potentially occur in the wetland and adjacent upland habitats. These would include the Pacific treefrog (Hyla regilla), garden slender salamander (Batracsops pacificus), and the California toad (Bufo boreas). Several of these species are known to frequent a variety of habitats from sea level to high into the mountains. They breed in marshes, lakes, ponds, roadside ditches, reservoirs, and slow streams in woods, meadows, and grassland, and are primarily ground dwellers found among low plant growth near a water source. Reptiles - Only one reptile species, the western fence lizard (Sceloporus occidentalis), was observed onsite during the surveys. Other reptile species expected to occur onsite include the western rattlesnake (Crotalus viridis), striped racer (Masticophis laterlis), common kingsnake (Lampropeltis getulus), and the gopher snake (Pituophis melanoleucus). 13 Mammals - Several mammal species were directly detected onsite. These include coyote (Canis latrans), Audubon's cottontail (Syvilagus audubonii), California ground squirrel (Spermophilus beecheyf), and raccoon (Procyon lotor). Runways of meadow mice (Microtis californicus) were observed in areas of the project site containing annual grasses. Birds - Approximately 27 species of birds were detected on this proposed park site during the survey (attachment B). Most of these species are typical inhabitants of Diegan coastal sage scrub and chaparral communities in Southern California. The following species were observed onsite: greater roadrunner (Geococcyx californianus), NuttalTs woodpecker (Picoides nutallti), scrub jay (Aphelocoma coerulescens). Brewer's blackbird (Euphagus cyanocephalus), northern mockingbird (Mimus polyglottos), and song sparrow (Melospiza melodia). Typical coastal sage scrub species which are residents of the site include the California quail (Callioeloa California*), Anna's hummingbird (Calypte anna), California gnatcatcher (Polioptila californica), wrentit (Chamaea fasciata), and California towhee (Pipilo crissalis). Although non-native grasses found on the project site do not contain sensitive or unique floral resources, these grasses may be considered important for wildlife species. This is due to the habitat and foraging area they provide for a variety of animal species when in conjunction with nearby sage scrub and riparian resources, as well as their proximity to intermittent water resources. Two red-tailed hawks (Buteo jamaicensis), a turkey vulture (Cathartes aura), a raven (Corvus corax) and an American kestrel (Falco sparverius) were observed flying over the site. Raptor species observed onsite or overhead presumably forage on the project site and at nearby properties. Zone 19 Park The small amount of native vegetation and the predominance of disturbed agricultural areas onsite are expected to provide only modest opportunity for wildlife in the area. For this reason, onsite wildlife consists of a limited representation of what normally would be expected in the 14 coastal foothills and valley grassland regions of San Diego County. The open character of much of the site, however, should attract a variety of foraging raptors. Wildlife species either observed or indicated by direct evidence are listed in attachments B and C of this report Wildlife species considered of high interest are discussed within the text of this report A relatively small number of reptile and mammal species were actually observed during the field reconnaissance. This is due, in part, to a variety of factors including time of year and the nocturnal and secretive habits of many species which may occur in the area, as well as the amount of site disturbance. The observed and expected fauna of the project site are discussed by taxonomic grouping below. Amphibians - No amphibians were detected during the survey period and none are expected due to a lack of appropriate habitat onsite. In general, amphibian species occur in wetland and adjacent upland habitats. Reptiles - Two reptile species were observed onsite during the surveys. These were the western fence lizard (Sceloporus occidentalis) and the gopher snake (Pituophis melanoleucus). Other reptile species expected to occur onsite include the western rattlesnake (Crotalus virldis), striped racer (Masticophis laterlis), and the common kingsnake (Lampropeltis getulus). Mammals - Four mammal species were directly detected onsite. These include coyote (Canis latrans), Audubon's cottontail (Syvilagus audubonii), California ground squirrel (Spermophilus beecheyi), and Botta's pocket gopher (Thomomys bottae), Birds - Approximately 27 species of birds were detected on this proposed park site during the survey (attachment B). Most of these species are typical inhabitants of chaparral and the coastal sage scrub communities in Southern California. Species occuring onsite in these habitats include: lesser goldfinch (Carduelis psaltria), morning dove (Zenaida macroura), greater roadrunner, Nuttall's woodpecker, scrub jay, rufus-sided towhee (Pipilo erythrophthalmus\ 15 savannah sparrow (Passerculus sandwichensis), and western meadowlark (Sturnella neglecta). Also observed flying overhead were a turkey vulture and a red-tailed hawk. Other species observed onsite, which may be residents, include the California quail (Callioeloa californica), Anna's hummingbird (Calypte anna), wrentit (Chamaeafasciata'), and California towhee (Pipilo crissalis). Although non-native grasses are found on the project site scattered throughout the chaparral vegetation and beneath the onsite oaks, they do not constitute a grassland, per se, and likely do not contain special interest plant resources. However, they may be considered important for some species of wildlife due to the habitat and foraging area they provide when in conjunction with nearby chaparral resources. A proximity to intermittent water resources is also an important aspect in the development of biological diversity for any site. One red-tailed hawk and a turkey vulture were observed flying over this project site. Raptor species observed onsite or overhead presumably forage on the project site and at nearby properties. Also observed onsite was a great horned owl (Bubo virginianus), which was seen roosting in one of the two large coast live oak trees located in the northeastern corner of the site. No raptor nests were observed during the survey. However, these large owls are known to utilize abandoned red-tailed hawk nests (Unitt 1984). SPECIAL INTEREST WILDLIFE SPECIES Alto Mira Park No animal species listed as threatened or endangered by state or federal agencies were detected during the survey and none are expected to occur onsite. However, two species considered sensitive by state, federal, or local resource conservation agencies were detected within the project boundary: California gnatcatcher and red-tailed hawk. Table 3 lists the special interest wildlife species known from the area of the Alta Mira park project site. Other sensitive species which may be expected, but were not observed onsite, include the San Diego homed lizard 16 TABLE 3 SPECIAL INTEREST WILDLIFE SPECIES KNOWN FROM THE PROJECT AREA SPECIES Black-Shouldered Kite California Gnatcatcher* San Diego Homed Lizard Cooper's Hawk Least Bell's Vireo Northern Harrier Orange-throated Whiptail Pacific Pocket Mouse Red-tailed Hawk* Willow Flycatcher Great Horned Owl* American Kestrel* STATUS Federal State CFP PFE CSC 2 CSC CSC FE CE CSC 2 CSC 2 CSC — FSS CSC — — * species observed onsite Source: Refer to Appendix C for an explanation of the status designation 17 ^ ^ (Phyrnosoma coronation blainvelli) and orange-throated whiptail (Cnemidophorus hyperythrus beldingi). Two California gnatcatchers were observed utilizing the coastal sage scrub onsite. This small, sedentary bird is ecologically thought to be restricted to the sage scrub plant community of Southern California. This species is currently under a proposal review by the U.S. Fish and Wildlife Service for federal listing as endangered. The California gnatcatcher is a permanent resident of the sage scrub community, a unique and diverse vegetation type that many experts consider to be one of the most endangered habitats in the continental United States (Atwood, 1990). The precise ecological requirements of the California gnatcatcher are not well known, and not all areas of sage scrub appear to be suitable habitat capable of supporting this species (Atwood, 1990). Subtle differences in plant species composition, vegetative structure, fire history, and geographic location may affect habitat suitability. Liberal estimates of the number of California gnatcatchers presently occurring in the United States range from 1,200 to 2,000 pairs (Atwood, 1990), with sizable and stable populations persisting in Orange, Riverside, and San Diego counties. No reliable data on the territory size of this bird in San Diego County have been published, although biologists working with the California gnatcatcher in San Diego County in the last few years (Sweetwater Environmental Biologist, 1986; WESTEC, 1987; ERCE, 1990) have indicated territories ranging from 2 to 14.5 acres. Extensive studies of color banded individuals by ERCE (1990) have indicated larger territories by up to 75%. For example, a pair of California gnatcatchers that spends most of its time within approximately 13 acres may, during the course of the breeding season use an area as large as approximately 23 acres. A total of two individuals (one pair) were observed on the project site. These two individuals limited their use of the site to the 8.5 acres of coastal sage scrub in the western portion of the Alta Mira site (Figure 3). Birds of prey (raptors) as a group are considered sensitive because of loss of foraging areas, their vulnerability to human disturbance, their low population densities, and their position at the top of the food chain. Raptor species observed flying over the site presumably forage there. Red- 18 tailed hawks are fairly common residents and winter visitors. They are most numerous around agricultural fields and grassland, but wandering individuals are often seen over any habitat. The San Diego homed lizard (Phrynosoa coronation blainvillei) is a candidate for federal listing (Category 2), protected by the California Department of Fish and Game and considered endangered by the San Diego Herpetological Society (SDKS, 1980) because of habitat destruction and collecting for the pet trade. No individuals were observed on die project site; however, habitat onsite (Diegan coastal sage scrub) may be appropriate. The orange-throated whiptail (Cnemidophorus hypeythrus beldingi) is a candidate for federal listing (Category 2), protected by the California Department of Fish and Game, and considered threatened by the San Diego Herpetological Society (SDKS, 1980). The principal threat to this species is the loss of open sage scrub, its preferred habitat No individuals were observed in the various locations and habitats surveyed throughout the project site. This species may also be expected to occur here. Zone 19 Park No animal species listed as threatened or endangered by state or federal agencies were detected during the survey and none are expected to occur onsite. Two species considered sensitive by stale, federal, and/or local resource conservation agencies were detected within the project boundary: great homed owl (Bubo virginianus)and red-tailed hawk. Other sensitive species which may be expected, but were not observed onsite, include the San Diego horned lizard (Phyrnosoma coronation blainvelli) and orange-throated whiptail (Cnemidophorus hyperythrus beldingi). Table 3 lists both the observed and expected wildlife species for the proposed Zone 19 park project site. Birds of prey (raptors) as a group are considered sensitive because of loss of foraging areas, their vulnerability to human disturbance, their low population densities, and their position at the top of the food chain. The red-tailed hawk observed flying over the site presumably forages here. 19 Red-tailed hawks arc fairly common residents and winter visitors. They are most numerous around agricultural fields and grassland, but wandering individuals arc often seen over any habitat A great horned owl was observed in the group of two large oak trees near the northeast corner of the site. This owl species is an uncommon resident of many different habitat types, including mature oaks and agricultural areas. They may be found wherever there are tall trees or buildings which provide cavities for nesting and/or daytime roosting. IMPACTS/CONSTRAINTS Alta Mira Park Development of a park on this site would potentially result in alteration of nearly all 42 acres. The following analysis is based on utilization of the entire area within the proposed park boundary and, therefore, assumes a worst-case scenario. The proposed project would result in the loss of approximately two acres of riparian scrub and floodplain habitat It would not be considered a significant biological effect of project implementation, in and of, itself because of its small size and isolated character. However, the loss of this wetland habitat would be considered significant under the "no net loss" policy of the California Department of Fish and Game. Mitigation at a ratio of at least 1:1 would be required for any alteration of this habitat, pursuant to a California Department of Fish and Game Section 1601 Streambed Alteration Agreement Loss of this habitat would be a significant adverse, cumulative impact, adding to the region-wide reduction of this habitat type. This habitat also acts as a buffer between the California gnatcatcher (sage scrub habitat) and adjacent agricultural activity onsite. The proposed Alta Mira Park project would also result in the loss of approximately 8.5 acres of Diegan coastal sage scrub. Loss of this habitat would be an adverse, cumulative impact, adding to the region-wide reduction of this habitat type. In addition, impacts to the coastal sage scrub supporting two California gnatcatchers would be considered significant due to the presence of California gnatcatchers and their current status. 20 Zone 19 Park No significant biological effects are anticipated to occur should development proceed at the proposed Zone 19 project site. Adverse, but not significant impacts which may be expected as a result of project implementation include: 1) the loss of approximately 10 acres of mixed chaparral habitat; 2) the loss of approximately 10-12 oak trees, two of which are of specimen size and are located near the northeast corner of the project site. A specimen oak is defined here as having a crown spread (diameter) of at least 10 feet; and 3) the loss of perching, roosting, and/or nesting opportunity which may result from the removal of onsite oak resources. Loss of these resources would be an adverse, cumulative impact, adding to the region-wide reduction in San Diego county. MITIGATION AND RECOMMENDATIONS It is generally recommended for each park site that excessive use of invasive landscape plant material not be utilized. Numerous species are known to take over large areas of native lands and out-compete the native wildlife species. Species such as ice plant, eucalyptus, and pampas grass are examples of such "pest" landscape species. It is recommended that drought tolerant, low invasive species be primarily utilized. Alta Mira Park Significant impacts at the Alta Mira Park site could potentially occur to coastal sage scrub habitat, riparian habitat, and the California gnatcatcher. Therefore, the following mitigation measures should be incorporated into the park design. The following mitigation measures are discussed in order of recommended priority. The significant impact to the onsite Diegan coastal sage scrub habitat and the two California gnatcatcher which currently use this resource should be avoided to the maximum extent feasible. Complete avoidance of these habitats will eliminate the need for any additional mitigation, park 21 development delays, andNor potential offsite mitigation land purchases. Once avoided, the area should be deeded into permanent open space, allowing only minimal encroachment by those potentially using the area. To avoid this sensitive resource, park design should include access to the site from the eastern parcel edge. Conversations with City staff indicate a planned park design which would allow site access from the east boundary of the parcel (Pers. Comm. P. Entezari). Based on this tentative agreement, there would be no significant impacts to these resources, and no further mitigation would be required. If, however, some impacts occur within these resources, then mitigation measures will be required. Mitigation measures for impacts to the coastal sage scrub and the one pair of California gnatcatcher would take the form of offsite mitigation land purchases. Property purchased for mitigating the coastal sage scrub impacts must support at least one pair of California gnatcatcher (regardless of acreage) and be contiguous to offsite permanent open space. The City of Carlsbad is currently preparing a City-wide Habitat Conservation Plan for the California gnatcatcher. Any purchases or mitigation measures for this project should be consistent and in conformance with the goals of that effort Impacts to the riparian scrub habitat onsite would require consultation with the California Department of Fish and Game for a Streambed Alteration Agreement (1600-1603). Revegetation of riparian habitat at a minimum ratio of 1:1 replacement would be required. The revegetation should take place within the same drainage onsite, if the entire drainage has not been impacted. If, however, the entire area is impacted, then offsite purchases and mitigation measures would be required. It should be noted that locations for wetland (riparian) revegetation efforts are becoming more scarce throughout the San Diego region and location of a suitable size parcel would be costly and time consuming. Impacts to the disturbed areas including dirt roads and agriculture do not require mitigation measures. 22 k „ Zone 19 Park No significant impacts were identified for this proposed park site. Therefore, no mitigation measures are required. It is recommended, however, that the canyon edges not be excessively filled. Filling of these areas may have negative effects on the canyon bottom in the long term. It is further recommended that the onsite oak trees be retained and incorporated into the park design. 23 LITERATURE CITED American Ornithologists' Union, committee on classification and nomenclature. 1986. Thirty-fourth supplement to the AOU Checklist of North American birds. The Auk 99(3). Attwood, J. 1990. Status Report of the California Gnatcatcher. USFWS, unpublished report. Beanchamp, ILM. 1986. A Flora of San Diego County. Sweetwater River Press. 241 pp. California Department of Fish and Game. 1990. Special Animals. Natural Diversity Data Base. Cowardin, LJvL, F.C Golet, and E.T. LaRoe. 1979. Classification of wetlands and deepwater habitats of the United States. U.S. Fish and Wildlife Service, U.S. Department of Interior, December. Entezari, Pat 1992. Project Manager, City of Carlsbad. Personal communication with Elyssa Robertson, January 1992. Holland, R-F. 1986. Preliminary descriptions of the natural communities of California. State of California, The Resources Agency. Jennings, MR. 1983. An annotated checklist of the amphibians and reptiles of California. California Department of Fish and Game 69(3):151-171. Munz, P.A. 1974. A flora of southern California. University of California Press, Berkeley. 1086pp. San Diego Herpetological Society. 1980. Survey and status of endangered and threatened species of reptiles natively occurring in San Diego County. Prepared for Fish and Wildlife Committee, San Diego Department of Agriculture. 33 pp. Smith, J.P., Jr. and K. Berg. 1988. Inventory of rare and endangered vascular plants of California. California Native Plant Society, special publication no. 1 (4th edition). Tate, J. Jr, and DJ. Tate. 1982. The Blue List for 1982. American birds 35(1)3-10. United States Army Corps of Engineers (ACOE). 1986. The Federal Manual for Identifying and Delineating Jurisdictional Wetlands. United States Department of Agriculture (USDA). 1973. Soil Survey, San Diego area, California. United States Fish & Wildlife Service. 1985a. Endangered and threatened wildlife and plants: Review of plant taxa for listing as endangered and threatened species; .Notice of review; Federal Register, 50(188): 39526-39527, September 27. United States Fish & Wildlife Service. 1985b. Endangered and threatened wildlife and plants. Review of taxa for listing as endangered or threatened species. Notice of review. Federal Register, 50(181), 37958-37967, September 18. Unitt, P. 1984. The Birds of San Diego County. 24 ATTACHMENT A Floral Species List ALTA MIRA/ZONE 19 PARK PROJECT SITES OBSERVED FLORAL SPECIES SPECIES ALTA MIRA ZONE 19 Amaranthaceae-Amaranth Family Amaranthus sp. XX Amarylladaceae Bloomeria crocea Dichelostemma pulchella X Anacardiaceae - Sumac Family Malosma laurina X X Rhus integrifolia X X Asclepiadaceae - Milkweed Family Asclepias sp. X Boraginaceae - Borage Family Heliotropiwn curassavicum X Pectocarya sp. X Cactaceae - Cactus Family Opuntia littoralis X X Caprifoliaceae - Honeysuckle Family Sambucus mexicana X Chenopodiaceae - Goosefoot Family Salsola iberica X X Compositae (Asteraceae) - Sun Flower Achillea millefolium X X Ambrosia psilostachya X Artemisia californica . X X Artemisia dracunculus X Baccharis glutinosa X X Baccharis sp. X X Centaurea sp. XX Circium sp. X X Corethrogyne filaginifolia X Haplopappus venetus X X SPECIES ALTA MIRA ZONE 19 Hemizonia fasciclata X Heterotheca grandifolora X X Lactuca serriola X X Malacothrix sp. X X Picris echioides X Xanthium strumarium X X Brassicaceae (Cruciferae) - Mustard Family Brassica sp. X X Ericaceae - Heath Family Xylococcus bicolor X Euphorbiaceae -Spurge Family Croton californicus X Eremocarpus setigerus X Euphorbia sp. X Ricinus communis X X Fagaceae - Oak Family Quercus agrifolia Geraniaceae - Geranium Family Erodium sp. X X Hydrophyllaceae - Waterleaf Family Phacelia sp. X Iridaceae -Iris Family Sisyrinchium bellum X Lamiaceae (Labiatae) - Mint Family Marrubium vulgare X Salvia mellifera XX Polemoniaceae - Phlox Family Navarretia sp. XX Polygonaceae - Buckwheat Family Eriogonum fasciculatum X X Rwnex crispus X X SPECIES ALTA MIRA ZONE 19 Rosaceae - Rose Family Adenostoma fasciculatwn X Heteromeles arbutifolia X Salicaceae - Willow Family Salix sp. X Solanaceae - Nightshade Family Nicotiana glauca X Apiaceae (Umbelliferae) - Carrot Family Foeniculwn vulgare X X ATTACHMENT B Faunal Species List ALTA MIRA/ZONE 19 PARK PROJECT SITES WILDLIFE LIST SPECIES BIRDS Family Cathartidae Turkey Vulture Cathartes aura Family Accipitridae Red-tailed Hawk Buteo jamaicensis Family Falconidae American Kestrel Falco sparverius Family Phasianidae California Quail Callipepla californica Family Columbidae Mourning Dove Zenaida macroura Family Cuculidae Greater Roadrunner Geococcyx californianus Family Strigidae Great Horned Owl Bubo virginianus Family Trochilidae Anna's Hummingbird Calypte anna Family Picidae Nuttall's Woodpecker Picoides nuttallii Family Tyrannidae Black Phoebe Sayornis nigricans Cassin's Kingbird Tyrannus vociferans Family Corvidae Scrub Jay Aphelocoma coerulescens American Crow Corvus brachyrhynchos Common Raven Corvus corax ALTA MIRA ZONE 19 X X X X X X X X X X X X X X X SPECIES ALTA MIRA ZONE 19 Family Paridae Plain Titmouse Parus inornatus X Family Aegithalidae Bushtit Psaltriparus minimus X X Family Troglodytidae Bewick's Wren Thryomanes bewickii X X Family Muscicapidae California Gnatcatcher Polioptila californica X Wrentit Chamaea fasciata X X Family Mimidae Northern Mockingbird Mimus polyglottos X X Family Bombycillidae Cedar Waxwing Bombycilla cedrontm X Family Emberizidae Subfamily Parulinae Orange-crowned Warbler Vermivora celata X Yellow-rumped Warbler Dendroica coronata X X Subfamily Emberizinae Rufous-sided Towhee Pipilo erythrophthalmus X California Towhee Pipilo crissalis X X Savannah Sparrow Ammodramus sandwichensis X X Song Sparrow Melospiza melodia X White-crowned Sparrow Zonotrichia leucophrys X Dark-eyed Junco Junco hyemalis X Subfamily Icterinae Western Meadowlark Sturnella neglecta X Brewer's Blackbird Euphagus cyanocephalus X Brown-headed Cowbird Molothrus ater X Family Fringillidae House Finch Carpodacus mexicamis X X Lesser Goldfinch Carduelis psaltria X X SPECIES ALTA MIRA ZONE 19 MAMMALS Coyote Cams latrans X X California Ground Squirrel Spermophilis beecheyi X X Botta's Pocket Gopher Thomomys bottae X X Audubon's Cottontail Syvilagus audubonii X X Raccoon Procyon lotor X Meadow Mouse Microtis californicus X REPTILES Western Fence Lizard Sceloporus occidentalis X X Gopher Snake Pituophis melanoleucus X ATTACHMENT C California Native Plant Society Listing and Sensitivity - Federal Candidate Species Designations CALIFORNIA NATIVE PLANT SOCIETY LISTING AND SENSITIVITY FEDERAL CANDIDATE SPECIES DESIGNATIONS California Native Plant Society (1988) List 1 = Plants of highest priority 1A = Plants presumed extinct in California IB = Plants rare and endangered in California and elsewhere List 2 = Plants rare and endangered in California, but common elsewhere List 3 = Plants about which we need more information List 4 = Plants of limited distribution (A watch list) CNPS R-E-D Code R (Rarity) 1 = Rare, but found in sufficient numbers and distributed widely enough that the potential for extinction or extirpation is low at this time. 2 = Occurrence confined to several populations or one extended population. 3 = Occurrence limited to one or a few highly restricted populations, or present in such numbers that it is seldom reported. E (Endangered) 1 = Not endangered 2 = Endangered in a portion of its range 3 = Endangered throughout its range D (Distribution) 1 = More or less widespread outside California 2 = Rare outside California 3 = Endemic to California FEDERAL CANDIDATE SPECIES DESIGNATIONS* Cl = Enough data are on file to support the federal listing. Cl = Enough data are on file to support federal listing, but the plant is presumed extinct. C2 = Threat and/or distribution data are insufficient to support federal listing. C3a = Extinct C3b = Taxonomically invalid C3c = Too widespread and/or not threatened *Source: Smith and Berg (1988) GEOTECHNICAL REPORT v,,, GEOTECHNICAL ENGINEERING INVESTIGATION AND GEOLOGIC RECONNAISSANCE FOR ALTA MIRA PARK CARLSBAD, CALIFORNIA PREPARED FOR THE DIKE PARTNERSHIP IRVINE, CALIFORNIA PREPARED BY GEOCON INCORPORATED SAN DIEGO, CALIFORNIA FEBRUARY 1992 GEOCON INCORPORATED Geotechnical Engineers and Engineering Geologists File No. 04786-54-01 February 5, 1992 The Dike Partnership One Venture Suite 100 Irvine, California 92718 Attention: Mr. Jim Ridge Subject: ALTA MIRA PARK CARLSBAD, CALIFORNIA GEOTECHNICAL INVESTIGATION AND GEOLOGIC RECONNAISSANCE Gentlemen: In accordance with your authorization and our proposal dated November 7, 1991, we have performed a geotechnical engineering investigation and geologic reconnaissance for the subject park site development. The accompanying report presents the findings from our study and our conclusions and recommendations relative to the proposed development of park site improvements. If you have any questions regarding this report, or if we may be of further service, please do not hesitate to contact this office at your convenience. Very truly yours, David RCE22527-/ EBR:JH:DFL:slc (10) addressee 6960 Flanders Drive San Diego, CA 92121-2974 619 558-6900 FAX 619 558-6159 Hoobs CEG 1524 Eric B. Rehwoldt Staff Engineer CERTIFIEDENGINEERING GEOLOGIST TABLE OF CONTENTS PURPOSE AND SCOPE 1 SITE AND PROJECT DESCRIPTIONS 2 SOIL AND GEOLOGIC CONDITIONS 4 Unsuitable Fill (Qusf) 5 Topsoil (unmapped) 5 Alluvium (Qat) 6 Terrace Deposits (Qt) 7 Delmar Formation (Td) 7 GROUNDWATER 9 GEOLOGIC HAZARDS 9 Faulting and Seismicity 9 Liquefaction 12 CONCLUSIONS AND RECOMMENDATIONS 13 General 13 Grading 14 Soil and Excavation Characteristics 17 Bulking and Shrinkage Factors 18 Slopes 19 Foundations 20 Concrete-Slabs-On-Grade 21 Retaining Walls 22 Lateral Loads 23 Corrosion Potential 24 Preliminary Pavement Recommendations 25 Site Drainage 28 Plan Review 28 LIMITATIONS AND UNIFORMITY OF CONDITIONS MAPS AND ILLUSTRATIONS Figure 1, Vicinity Map Figure 2, Geologic Map (Map Pocket) Figures 3a - 3b, Slope Stability Analysis Figures 4a - 4b, Surficial Slope Stability Analysis Figure 5, Wall/Column Footing Dimension Detail Figure 6, Retaining Wall Drainage Detail APPENDIX A FIELD INVESTIGATION Figures A-l through A-20, Logs of Trenches TABLE OF CONTENTS (CONTINUED) APPENDIX B LABORATORY TESTING Table B-I, Summary of In-place Moisture-Density and Direct Shear Test Results Table B-II, Summary of Laboratory Maximum Dry Density and Optimum Moisture Content Test Results Table B-ITf, Summary of Expansion Index Test Results Table B-IV, Summary of Water Soluble Sulfate and Chloride, pH and Resistivity Test Results Table B-V, Summary of R-Value and Sand Equivalent Test Results Figure B-l, Consolidation Curve APPENDIX C RECOMMENDED GRADING SPECIFICATIONS File No. 04786-54-01 February 5, 1992 GEOTECHNICAL ENGINEERING INVESTIGATION PURPOSE AND SCOPE This report presents the results of the geotechnical engineering investigation conducted for the proposed Alta Mira Park, located adjacent to the east side of Paseo Del Norte and north of Camino del las Ondas in the city of Carlsbad, California (see Figure 1, Vicinity Map). The purpose of our investigation was to evaluate the surface and subsurface soil and geologic conditions at the site and, based on the conditions encountered, to provide preliminary recommendations pertaining to the geotechnical aspects of project development as presently proposed. The scope of the this geotechnical engineering investigation consisted of a field investigation, laboratory testing and a data evaluation including review of the following: 1. Kennedy, M. P., Geology of the San Diego Metropolitan Area, California, California Division of Mines and Geology, Bulletin 200. 1975. 2. On the Manner of Deposition of the Eocene Strata in Northern San Diego County, edited by San Diego Association of Geologists, April 14, 1985. 3. Conceptual Plan and Access Study, Alta Mira Community Park, Carlsbad, California, scale: 1 inch equals 100 feet, prepared by the City of Carlsbad, dated February 1991 (Figure 2). 4. Alta Mira Park Topographic Map, Carlsbad, California, graphic scale: 1 inch equals 100 feet, prepared by Crosby Mead Benton & Associates, dated December 13, 1991. File No. 04786-54-01 February 5, 1992 The field investigation consisted of a site reconnaissance by representatives from our firm and the excavation of twenty exploratory trenches. Laboratory tests were performed on selected soil samples obtained at various depths in the exploratory trenches to evaluate pertinent physical properties of the soils encountered. Details of our field exploration and laboratory tests are presented in Appendices A and B, respectively. The base map used for this study consisted of the referenced conceptual grading plan, dated February, 1991. The location of exploratory trenches is depicted on the Geologic Map, Figure 2 (Map Pocket). The recommendations presented herein are based on an analysis of the data obtained from the exploratory borings, laboratory tests and our experience with similar soil and geologic conditions. SITE AND PROJECT DESCRIPTIONS The site encompasses approximately 42 acres of undeveloped land located on the east side of Paseo del Norte and north of Camino del las Ondas. The proposed Kelley Road delineates the eastern property boundary. The central and eastern portions of the site are dominated by cultivated fields. The extreme western portions of the site are presently undeveloped and support a dense cover of native grasses and shrubs. No permanent structures exist on the site. - 2- File No. 04786-54-01 February 5, 1992 Topographically the site is characterized by a series of rounded ridges and narrow tributary drainages which gently slope westward and intersect a broad, alluviated, north-draining canyon course. Paseo del Norte marks the western property limits at the top of a steep natural slope which descends eastward and intersects the broad, alluviated drainage within the western portions of the property. The height of this existing slope is approximately 45 feet. Site elevations vary from a low of approximately 90 feet Mean Sea Level (MSL) within the northwestern corner of the property to a high of approximately 190 feet MSL along the eastern property limits. The elevation along the top of the slope adjacent to Paseo del Norte at the western property limits is approximately 155 MSL. It is anticipated that the general development and grading will be contained within the property boundaries with no off-site grading or improvements planned at this time. Planned improvements include a main community center building, tennis complex, soccer complex, ball field complex, hardcourt complex, passive areas, and associated concession buildings and restrooms. Retaining walls, hardscape areas and paved automobile parking and driveway areas will also be constructed. Based on review of the referenced conceptual grading plan, it is anticipated that cut and fill depths will be on the order of 12 feet and 10 feet, respectively. Cut excavations will generally occur within the ridge areas within the eastern portions of the property, while fills will be placed within drainages and lower ridge areas in the central portions of the site. Cut and fill slopes inclined at 2:1 (horizontalrvertical) with maximum heights on the order of 10 3 File No. 04786-54-01 February 5, 1992 feet are anticipated west of the main community center building. Based on conversations with Jim Ridge of the Dike Partnership, and Pat Entezari of the City of Carlsbad, grading and roadway improvements in the vicinity of the north-draining canyon course within the western portions of the property, as depicted on the referenced grading plans, are no longer being pursued. It is our understanding that project grading will be generally limited to areas presently cultivated for agriculture use. The descriptions contained herein are based upon a site reconnaissance, the conceptual grading plans referenced and discussions with representatives of The Dike Partnership and the City of Carlsbad. If project details vary significantly from those outlined, Geocon Incorporated should be notified for review and possible revision of recommendations presented herein. SOIL AND GEOLOGIC CONDITIONS Based on review of the available literature and evidenced by our field investigation, the soils underlying the site consist of three surficial soil deposits, including unsuitable fill soils, topsoils and alluvium, and two formational units, including Terrace Deposits and the Delmar Formation. The areal distribution of these units is shown on the Geologic Map, Figure 2. Each of the surficial soil types and representative geologic units encountered is described below in order of increasing age. The symbols in parentheses following each soil type or geologic unit correspond to the geologic abbreviation used for mapping purposes on Figure 2. In addition, numbers shown adjacent to each trench excavation depicted on - 4- File No. 04786-54-01 February 5, 1992 Figure 2 indicate the approximate depth of surficial soils at that location requiring removal and recompaction in proposed fill areas. Where surficial soils are less than 3 feet in thickness, depth of surficial soils has not been indicated. Unsuitable Fill (Ousft Unsuitable fill consisting of trash debris imported to the site (wood, plastic, shoes, brush, etc.) mixed with soil materials are not suitable for use in engineered fills and should be exported from the site prior to the commencement of grading operations. Mounds of trash debris and unsuitable fill soils encountered were generally confined to the northern limits of the property. The approximate locations of these materials are shown on the Geologic X*^ Map (Figure 2) where thicknesses are anticipated to exceed 3 feet. The maximum thickness of unsuitable fill materials where indicated on Figure 2 is anticipated to be on the order of 6 feet. Topsoil f unmapped) A thin (1- to 3-foot-thick) veneer of loose, moist, dark brown to grayish brown, fine to medium sand with some silt and clay was found to overlie the Terrace Deposits and Delmar Formation within the higher profile ridge areas. Disturbed formational soils (Terrace Deposits) were often found to be mixed with topsoils in areas which had been extensively cultivated or graded for equipment access. Due to the porous and unconsolidated nature of the topsoil deposits and disturbed formational soils, they are not suitable in their present <****• condition for support of settlement-sensitive structures or additional fill. Remedial grading w - 5- File No. 04786-54-01 February 5, 1992 measures in the form of removal and recompaction of these materials within areas to receive additional fill is recommended as discussed hereinafter. Alluvium (Oaft Alluvial deposits were encountered within the narrow tributary drainages in the central and southern portions of the site, as well as the main, north-draining canyon area within the western portions of the site. Alluvial soils were found to overlie formational soils of the Terrace Deposits and Delmar Formation. Alluvial soils generally consisted of loose, moist to wet, light brown medium sand with silt and gravel, and dark brown to grayish brown, silty to clayey, fine to medium sand with little gravel. Lenses of subrounded gravel and cobble deposits typically were encountered near the base of the alluvial deposits. Cobble material encountered was on the order of 4 inches in maximum dimension. Groundwater was found perched within the alluvial soils and within the upper, weathered portions of the underlying formational deposits in Trench Nos. T-3 and T-10. Caving associated with the loose, saturated conditions of the alluvial deposits were observed as well within the indicated trenches. The maximum alluvial thicknesses encountered within the project site were on the order of 6 feet. Alluvial soils are considered unsuitable in their present condition to receive structural fill or settlement sensitive improvements. Remedial grading measures in the form of removal and recompaction of alluvial soils in areas to receive additional fill soils are recommended as discussed hereinafter. - 6- File No. 04786-54-01 February 5, 1992 Terrace Deposits (Ot} Quaternary-age Terrace Deposits generally consist of dense, rust brown, moist, silty to clayey, fine to coarse-grained sandstone were encountered below surficial soil deposits above an approximate elevation of 128 feet MSL across the project site. Terrace Deposit sandstones encountered were weakly cemented and friable and characterized by isolated, very dense, moderately-well cemented lenses. Occasional interbeds of greenish gray and rust brown, clayey sands and sandy clays within the Terrace Deposits were encountered in Trench Nos. T-l, T-2, T-7, T-ll, T-14, T-15 and T-20. Perched groundwater and caving conditions were encountered within gravelly interbeds and highly weathered portions of the Terrace Deposits within Trench Nos. 16, 18 an 19. Based on laboratory test results and previous experience with similar soil material, the Terrace Deposits generally possess a relatively high strength and low consolidation potential, and provide suitable foundation support characteristics in either an undisturbed or properly compacted condition. The clayey portion of the Terrace Deposits, however, possess a "medium" expansion potential (Expansion Index less than 90 as determined by UBC Standard 29-2) and will require special consideration during grading operations, as discussed herein. Delmar Formation (Td) The Tertiary-age (probable middle Eocene-age) Delmar Formation underlies surficial deposits and Terrace Deposits below an approximate elevation of 128 feet MSL within the - 7- File No. 04786-54-01 February 5, 1992 western portions of the site. According to cited references, the lithology (and thereby the engineering characteristics) of the Delmar Formation has not been distinctly differentiated from deposits of the younger Friars Formation at the project location. Where encountered in exploratory trenches, the Delmar Formation consists of interbedded, dense, light to medium gray, clayey, fine to coarse sandstone and very stiff to hard, grayish brown to greenish gray, sandy claystone. Sandstone beds are typically weakly cemented and friable, while claystone beds are fractured, blocky and exhibit shiny parting surfaces. Perched groundwater was encountered within the upper, weathered portions of the Delmar Formation below alluvial deposits within Trench Nos. T-3 and T-10. Based on previous experience with similar materials, formational soils of the Delmar Formation typically possess low consolidation characteristics; however, clayey portions of this formation have been found to possess a "medium" to "high" expansion potential. Although units of the Delmar Formation are not anticipated to be exposed at finish grade elevations within proposed cut areas, it is likely that remedial grading operations may generate spoils from the Delmar Formation within the central and western portions of the site. Remedial grading operations should be planned so that the cuttings from the clayey portions of the Delmar Formation are placed within deeper portions of proposed fills, as recommended hereinafter. - 8- File NO 04786.54.01 February 5, 1992 GROUNDWATER Perched groundwater was encountered within alluvial soils and within the upper, weathered portions of the formational soils within Trench Nos. T-3, T-10, T-16, T-18 and T-19. Perched groundwater conditions were generally encountered in the lower tributary drainages and ridge areas in the central and western portions of the site. In addition to the perched groundwater conditions encountered, topsoil and alluvial deposits were typically moist to wet throughout the site. The wet surficial soils and perched groundwater conditions are believed to reflect the periods of intense rainfall experienced shortly before the initiation of the field investigation, as well as the constant infiltration of irrigation water into the site soils generated from agricultural activity within the property. The presence and rate of groundwater seepage into trench excavations varied significantly throughout the project site. However, due to the limited extent and thickness of the alluvial soils present, groundwater is not anticipated to significantly impact grading operations during the summer months, but may be a consideration during the rainy season. In addition, consideration should be given to terminating irrigation on the site several months before grading is initiated. GEOLOGIC HAZARDS Faulting and Seismicity The results of our field investigation and a review of published geologic maps and reports indicates the site is not traversed by any known fault traces. The seismicity of the site is - 9- File No. 04786-54-01 February 5, 1992 influenced by both local and regional fault systems within the southern California and northern Baja California regions. The following table lists the fault zones which present the majority of the seismic hazard to the site. TABLE! LOCAL AND REGIONAL FAULTS FAULT Rose Canyon Coronado Banks* Elsinore San Diego Trough* Newport-Inglewood* San Clemente* San Jacinto San Miguel San Andreas DISTANCE FROM SITE (MILES) 7 19 25 30 42 47 48 61 70 MAXIMUM CREDIBLE EARTHQUAKE MAGNITUDE 7.0 6.75 7.5 6.5 7.5 7.25 7.5 7.0 8.0 *Offshore Fault -10- File No. 04786-54-01 February 5, 1992 The Rose Canyon Fault is located approximately 7 miles west of the site. This fault is classified as an active fault by the California Division of Mines and Geology (CDMG). Portions of the fault are contained within an Alquist-Priolo Special Studies Zone. A series of earthquakes occurred in 1985 within the southern portion of San Diego Bay which were inferred to be along a strand of the Rose Canyon Fault. The largest earthquake recorded was approximately Magnitude 4.7. Historically, the Rose Canyon Fault zone has exhibited low seismicity with respect to earthquakes in excess of Magnitude 5.0. The offshore faults have exhibited a higher level of seismicity with historical earthquake magnitudes of 5.0 to 5.5. The more distant regional fault systems have historically experienced relatively high levels of seismicity. The distance from the regional faults to the site is such that the seismic hazard from those faults is considered low. The Rose Canyon, Elsinore and offshore fault zones present the greatest seismic hazard to the property. It is our opinion that the site would be subjected to moderate-to-severe ground shaking in the event of a major earthquake along any of the active or potentially active faults in the southern California or northern Baja California region. However, the seismic risk at the site is not considered to be significantly different than that of the surrounding developments. It is recommended that proposed structures be designed in accordance with the minimum seismic requirements as designed by the most recent edition of the Uniform Building Code. -11- File No. 04786-54-01 February 5, 1992 Liquefaction Soil liquefaction is generally limited to granular soils located below the water table which are in a relatively loose, unconsolidated condition at the time of a moderate to large seismic event. Due to the presence of near-surface, dense formational soils and the lack of a permanent near-surface groundwater table, the potential for seismically-induced liquefaction occurring within the site is considered low. -12- File No. 04786-54-01 February 5, 1992 CONCLUSIONS AND RECOMMENDATIONS General 1. It is our opinion that no soil or geologic conditions were encountered which would preclude the development of the property as currently proposed, provided the recommendations of this report are followed. 2. The site is underlain by surficial soils consisting of unsuitable fill, topsoils, alluvium, and by two formational soil deposits. The surficial soils are generally considered to be unsuitable in their present condition to receive settlement sensitive improvements and/or additional fill soils. Except for the unsuitable fill soils (mixture of soils and trash debris), which should be exported from the site, the remaining material should be removed and recompacted in the areas to be graded. 3. Laboratory testing indicates that clayey portions of the Terrace Deposits possess a "medium" expansion potential (as determined by UBC Standard Table 29-2). Expansive soils will require special consideration during site development as recommended hereinafter. 4. Perched groundwater was encountered within alluvial soils and gravelly lenses of the Terrace Deposits within the lower tributary drainage courses and ridge areas of the central portion of the subject property. Heavy rains prior to the field investigation, - 13- File No. 04786-54-01 February 5, 1992 as well as infiltration of irrigation water into site soils are believed to be the source of the observed groundwater condition. However, due to the relatively limited extent and thickness of alluvial deposits present, as well as the cessation of agricultural activities on the site prior to grading operations, groundwater is not anticipated to significantly impact grading operations during the summer months, but may be a consideration during the rainy season. Consideration should be given to discontinuing site irrigation operations several months, or as soon as practical, before grading is initiated. Grading 5. All grading at the site should be performed in conformance with the Grading Ordinance of the City of Carlsbad and the attached Recommended Grading Specifications (Appendix C). If the recommendations of this section of the report conflict with those of Appendix C, this section takes precedence. All earthwork should be observed by, and all compacted fill tested by, representatives of Geocon Incorporated. 6. Prior to commencing grading, a preconstruction conference should be held at the site with the owner or developer, city representation, grading contractor, civil engineer and geotechnical engineer in attendance. Special soil handling and/or the grading plans can be discussed at that time. -14- File No. 04786-54-01 February 5, 1992 7. Site preparation should begin with the clearing of all vegetation and deleterious debris of existing structures and utilities from the site. The depth of removal should be such that material to be used in fills is generally free of organic matter. All trash, metals, and other unsuitable fill materials, including material generated during stripping operations should be exported from the site and should not be used in fills. 8. Potentially compressible surficial deposits including topsoil and alluvium should be removed to firm natural ground and properly compacted prior to placing additional fill and/or structures. Estimated depths of removal of surficial deposits where observed within exploratory trench excavations are indicated on Figure 2. It should be noted that surficial soil thicknesses indicated on Figure 2 are representative of removal depths anticipated at the particular observation location. The actual extent of removals should be determined in the field by the soil engineer or engineering geologist. 9. Cut/fill transitions are anticipated beneath the proposed community center building pad, as well as other outlying clubhouse and concession facilities. Where transitions are encountered between compacted fill soils and formational soils within building pads, formational soils should be excavated (undercut) to a depth of 3 feet below pad grade. The excavated soils should then be compacted per the recommendations presented in Paragraph 11. The formational soil overexcavation should extend at least 10 feet horizontally beyond the building footprint and beyond the fill - 15- i^ File No. 04786-54-01 ^•^ February 5, 1992 soil/formational soil contact such that a minimum 3-foot fill thickness is maintained below the building. Representatives of Geocon Incorporated should evaluate the finish grade soil conditions to verify and modify the areas requiring formational soil undercut excavations. 10. Isolated, clayey portions of the Terrace Deposits and Delmar Formation exhibit a "medium" expansion potential (Expansion Index less that 90), based on the results of laboratory testing and experience with similar soil materials. To reduce the potential for expansion-related movement within proposed buildings areas it is recommended that a "low" expansive (Expansion Index less than 50), granular soil cap be placed within the upper 3 feet of pad grade elevation for these areas. Where clayey Terrace Deposits are exposed at building pad grade, or where less than 3 feet of additional fill soil will be placed on clayey formational soil, it is recommended that the formational soils be undercut to a depth that results in a 3-foot-thick layer of granular, "low" expansive soil below building pad grade. This granular soil cap should extend at least 10 feet beyond the building footprint. Excavated soils should be replaced and compacted in overexcavations per the recommendations presented in Paragraph 11. In addition, it is recommended that a "low" expansive, granular soil cap be placed within 2 feet of subgrade elevations within hardscape and hardcourt areas. This 2-foot granular soil cap should extend a minimum of 5 feet beyond the hardscape and hardcourt areas. In our opinion, granular soil material suitable for "capping" building pads and hardscape areas may be generated on-site and will likely - 16- File No. 04786-54-01 February 5, 1992 require no importation of additional granular materials; however, grading operations should be carefully planned to place potentially expansive soils encountered during cut operations and remedial grading operations into the deeper fill areas. 11. Areas to receive fill (including the bottom of undercut excavations) should be scarified to a depth of 12 inches, properly moisture conditioned to at least 2 percent above optimum moisture content and recompacted. Fill soils derived from on-site cutting operations may then be placed and compacted in thin lifts until design elevations are attained. Fill soils (including trench backfill and scarified ground surfaces) should be compacted to a minimum 90 percent of the maximum dry density as determined by ASTM Test Procedure D1557-78 at a moisture content of 2 percent above the optimum moisture content. 12. Based on a review of the Conceptual Plan, canyon subdrains are not recommended at this time. Once a finalized grading plan has been prepared, Geocon Incorporated should review proposed grading to verify if canyon subdrains are required. Soil and Excavation Characteristics 13. In general, the soil conditions encountered range from "low" to "medium" expansive, silty and clayey, fine to medium sands derived from the Terrace deposits, clayey sands and sandy plastic clays derived from the Delmar Formation, and 'Very low" to "low" expansive, sandy alluvial soils. - 17- File No. 04786-54-01 February 5, 1992 14. In our opinion, the surficial soil deposits can be excavated with relatively light effort with conventional grading equipment. Excavation of the formational soils should require moderate to heavy effort. Bulking and Shrinkage Factors 15. Estimates of bulking and shrinkage factors are based on comparing laboratory maximum density test results with the density of the material in its natural state as encountered in the excavations. It should be emphasized that variations in natural soil density, as well as in compacted fill densities, render shrinkage value estimates very approximate. As an example, the contractor can compact the fill soils to any relative compaction of 90 percent or higher of the maximum laboratory density. Thus, the contractor has approximately a 10 percent range of control over the fill volume. Based on the limited work performed to date, the following earthwork factors are recommended as a preliminary basis for estimating how much the on-site soils may shrink or swell (bulk) when excavated from their natural state and placed as compacted fills. Soil Unit Shrink/Bulk Factor Alluvium 10 to 15 percent shrink Terrace Deposits 1 to 5 percent bulk -18- File No. 04786-54-01 February 5, 1992 Slopes 16. The stability of proposed cut slopes excavated within Terrace Deposit formational soils, and fill slopes constructed of granular soils derived from the Terrace Deposits, was analyzed utilizing the Janbu Dimensionless Parameter Analysis presented on Figure 3, included herein. The maximum anticipated height of cut or fill slopes is 10 feet inclined at 2:1 (horizontal:vertical). Shear strength parameters implemented in the slope stability analysis are based on laboratory tests performed on the Terrace Deposit formational soils and our experience with similar soil materials. The results of this analysis indicates that the calculated factor of safety against deep seated failure within cut slopes is greater than 1.5. 17. Surficial stability of proposed cut and fill slopes was analyzed utilizing the infinite slope analysis method and the shear strength parameters indicated above. The surficial slope stability analysis is presented on Figure 4. Analysis results indicate that the calculated factor of safety against surficial slope instability is greater than 1.5. To reduce erosion of cut or fill slopes, slopes should be planted, drained and properly maintained. 18. Cut slopes should be observed by the project engineering geologist during grading to verify that the exposed soil and geologic conditions do not differ significantly from those anticipated. -19- File No. 04786-54-01 February 5, 1992 Foundations 19. The following foundation recommendations are based on the assumption that "low" expansive, granular soils are present within 3 feet of proposed building pads. In addition, we have assumed that the maximum fill depth below proposed structures shown on the Conceptual Plan is less than 20 feet and that the fill differential is less than 10 feet. If grading plans or structure type change sufficiently to make our assumptions invalid, then Geocon Incorporated should be contacted to modify the following recommendations. Conventional continuous strip and/or isolated spread footings having a minimum width and depth of embedment below lowest adjacent soil pad grade of 12 inches and 18 inches, respectively, may be used for support of the proposed buildings. Footings with the above minimum foundation dimensions may be designed for an allowable soil bearing capacity of 2,500 psf when founded in properly compacted fill or dense formational soils. The allowable bearing pressure recommended may be increased up to one-third for transient loads such as wind or seismic forces. 20. Isolated spread footings which are a minimum of 2-foot-square and founded 18 inches below lowest adjacent pad grade in properly compacted fill soils or dense forma- tional soils may be designed for an allowable soil bearing pressure of 3,000 psf. This soil bearing pressure may be increased by 500 psf for each additional foot of width or depth to .a maximum allowable soil bearing pressure of 5,000 psf. Foundations located adjacent to slopes should be situated such that the lower outside - 20- File No. 04786-54-01 February 5, 1992 edge of the footing is at least 7 feet horizontally from the slope face. Figure 5 presents a detail of the above footing dimensions. 21. Continuous footings should be reinforced with two No. 4 reinforcing bars, one placed near the top and one placed near the bottom. Reinforcement of spread footings should be designed by the project structural engineer. Steel reinforcement is based on soil support characteristics and is not intended to be in lieu of structural requirements. Concrete-Slabs-On-Grade 22. Concrete slabs-on-grade should have a thickness of at least 4 inches. It is recommended that the minimum slab reinforcement consists of No. 3 steel reinforcing bars place 24 inches on center in both directions and positioned within the upper one- third of the slab. If the slabs are to receive additional concentrated loads such as those from forklifts or other equipment, then consideration should be given to increasing the slab thickness to at least 5 inches. The actual concrete slab thickness should be designed by the project structural engineer based on a modulus of subgrade reaction of 150 pci. -21- File No. 04786-54-01 February 5, 1992 23. The concrete slabs-on-grade should be underlain by at least 4 inches of clean sand, and where moisture sensitive floor coverings are planned, a visqueen moisture barrier placed at the midpoint of the sand cushion should also be provided. 24. The recommendations presented herein are intended to reduce the potential for cracking of the slabs and foundations due to the presence of expansive soils and differential fill thicknesses. However, even with the incorporation of the recom- mendations presented herein, foundations and slabs-on-grade may still exhibit some cracking. The occurrence may be reduced and/or controlled by limiting the slump of the concrete, proper concrete placement and curing, and by the placement of crack control joints at periodic intervals and, in particular, where re-entry slab corners occur. Retaining Walls 25. Continuous footings having a minimum width and depth of embedment below lowest adjacent soil pad grade of 12 inches may be used for support of proposed retaining walls. Footings with the above minimum foundation dimension may be designed for an allowable soil bearing capacity of 2,000 psf when founded in properly compacted fill or dense formational soils. Active earth pressures against walls will depend upon backfill and restraint conditions. Unrestrained walls should be designed to resist an active pressure equivalent to that generated by a fluid weighing 35 pcf. For rigid, absolutely restrained walls, an additional uniform pressure of 7H psf (where H equals - 22- File No. 04786-54-01 February 5, 1992 the wall height in feet) should be added to the above loading. These values assume that granular soil material will be used for backfill, the backfill surface will be level, and that no surcharge loads or hydrostatic pressures are applied to the wall. For sloping backfill inclined at 2:1 (horizontakvertical) behind the wall, an active earth pressure equivalent to that exerted by a fluid weighing 45 pcf should be assumed. Retaining walls subject to vehicle and light truck traffic surcharge within a horizontal distance equal to or less than the height of the wall should be designed for an additional uniform horizontal pressure of 75 psf. If a surcharge of moderate-to-heavy truck traffic is anticipated, Geocon Incorporated should be contacted to possibly modify retaining wall recommendations. 26. Retaining walls should be properly waterproofed in accordance with the requirements of the project architect and provided with wall drainage systems to reduce the potential for hydrostatic pressure buildup behind walls. Recommended wall drainage details for a typical concrete or block masonry retaining wall which assumes a level backfill and no surcharge loads is presented on Figure 6, included herein. Geocon Incorporated should be contacted if additional recommendations for wall drainage systems are required and/or if alternative retaining wall designs are being considered. Lateral Loads 27. The pressure exerted by an equivalent fluid weight of 300 pcf should be used to provide resistance to design lateral loads. This design value assumes that footings or - 23- File No. 04786-54-01 February 5, 1992 shear keys are poured neat against properly compacted fill soils and that the soil mass extends at least 5 feet horizontally from the face of the footing or three times the height of the surface generating passive pressures, whichever is greater. The upper 12 inches of material not protected by floor slabs or pavement should not be included in the design for passive resistance. 28. If friction is to used to resist lateral loads, a coefficient of friction between soil and concrete of 0.35 may be utilized. **•»* Corrosion Potential \^S 29. The laboratory tests performed on the predominant soil types yielded maximum water soluble sulfate and chloride contents of 0.03 percent. Based on these laboratory results and Table 7-851.3D of the Caltrans Highway Design Manual, no special cement requirements are considered necessary for concrete structures. It is recommended, however, that a concrete materials engineer be consulted to provide additional recommendations in order to minimize potential premature disintegration of concrete due to chemical and physical agents. 30. Resistivity and pH tests were performed on representative soil samples utilizing Test Method No. California 643, 1978, Department of Transportation, Division of Construction, Method for Estimating the Service Life of Steel Culverts. Test results yielded a pH of 6.8 and a minimum resistivity of 530 ohm-cm. This value of - 24- File No. 04786-54-01 February 5, 1992 resistivity is considered indicative of a potentially corrosive environment for steel pipe and metal culverts. The above laboratory results correspond to a period of 14 years to perforation for a 16-gauge metal culvert and 37 years to perforation for an 8-gauge metal culvert, based on Figure 7851.3 of the Caltrans Highway Design Manual. It is recommended that further tests be performed and evaluated by a cathodic engineer once the final grading and underground plans are available to take the necessary precautions to avoid premature corrosion on underground pipes and buried metal structures. Laboratory test results performed to evaluate the corrosion potential of the site soils on concrete and metal structures is summarized in Appendix B, Table B-IV. Preliminary Pavement Recommendations 31. The following pavement recommendations are based on R-value test results on soil samples representative of the anticipated pavement subgrade materials. R-Value and Sand Equivalent test results are presented in Appendix B, Tables B-V. For preliminary design purposes, Traffic Index values of 4.5 for automobile parking areas and 6.5 for driveways and areas subjected to occasional heavy truck traffic have been assumed in pavement section design calculations. These pavement section designs should be verified when samples of parking lot and driveway area subgrade soils have -25- File No. 04786-54-01 February 5, 1992 been obtained for R-value testing. Pavement calculations presented below are base on Table 604.B of the Caltrans Highway Design Manual. Location Asphalt Concrete (inches) Class II Aggregate Base (inches) Automobile Parking Areas 3 6 Driveways and Occasional Truck Traffic Areas 4 8 32. Laboratory testing indicates that soils anticipated to be encountered at pavement subgrade elevations within clayey portions of the Terrace Deposit formational soils and fill soils derived from the Terrace Deposits are estimated to possess a "medium" expansion potential (UBC Expansion Index less than 90). Where "medium" expansive subgrade soils are determined to be of sufficient areal extent and thickness, it is recommended that these soils be removed to a depth of 1 foot below subgrade elevations and replaced with on-site granular soils possessing an Expansion Index less than 50. Excavated removal bottoms should be scarified to a depth of 12 inches, moisture conditioned and recompacted to 90 percent relative compaction. Soils placed within excavated removals should be moisture conditioned and compacted to a minimum of 95 percent relative compaction. -26- File No. 04786-54-01 February 5, 1992 33. Prior to placing base material, subgrade soils should be scarified, moisture conditioned at optimum moisture content and recompacted to a minimum of 95 percent relative compaction. The depth of compaction should be at least 12 inches. 34. Class n base should conform to Section 200-2.3.2 of the Standard Specifications for Public Work Construction (Green Book). The asphalt concrete should conform to Section 203-6 of the Green Book. 35. Where trash bin enclosures are planned, the pavement sections should consist of 6 inches of portland cement concrete placed on properly compacted subgrade soil s*****' as recommended above. No Class II base will be required. The concrete should extend into the roadway sufficiently so that the front wheels of the trash truck are on the concrete when loading. 36. Planter areas adjacent to pavement areas are not recommended due to the potential for the infiltration of water beneath the pavement. This can result in premature pavement failure. Where landscaping planters are desired in pavement areas, it is suggested that either subdrains, which collect excess irrigation water and transmit it to drainage structures, or impervious, above-grade planter boxes be used. In addition, it is recommended that consideration be given to providing a cutoff wall, geocomposite strip drains, or a deepened curb along the edge of the pavement that extends to at least 6 inches below the subgrade soil.w - 27- File No. 04786-54-01 February 5, 1992 Site Drainage 37. Adequate drainage provisions are imperative. Infiltration of irrigation water excess and storm water runoff in supporting soils can adversely affect the performance of the planned improvements. Under no circumstances should water be allowed to pond adjacent to footings or pavement edges. The site should be graded and maintained such that surface drainage is directed away from structures and the top of slopes into swales or other controlled drainage devices. All roof and pavement drainage should be directed onto splashblocks or into conduits which carry runoff away from proposed structures or pavement areas. 38. Site irrigation should be monitored for a sufficient period after installation of irrigation facilities to determine the appropriate amount of irrigation necessary to maintain landscaping without over-watering. 39. Area drains, canyon subdrains, and other site drainage facilities should be properly maintained. Plan Review 40. Geocon Incorporated should review grading and foundation plans prior to the submittal of the final design. Additional comments and recommendations can be determined at that time. -28- File No. 04786-54-01 February 5, 1992 LIMITATIONS AND UNIFORMITY OF CONDITIONS 1. The recommendations of this report pertain only to the site investigated and are based upon the assumption that the soil conditions do not deviate from those disclosed in the investigation. If any variations or undesirable conditions are encountered during construction, or if the proposed construction will differ from that anticipated herein, Geocon Incorporated should be notified so that supplemental rec- ommendations can be given. The evaluation or identification of the potential presence of hazardous materials was not part of the scope of services provided by Geocon Incorporated. 2. This report is issued with the understanding that it is the responsibility of the owner, or of his representative, to ensure that the information and recommendations contained herein are brought to the attention of the architect and engineer for the project and incorporated into the plans, and the necessary steps are taken to see that the contractor and subcontractors carry out such recommendations in the field. 3. The findings of this report are valid as of the present date. However, changes in the conditions of a property can occur with the passage of time, whether they be due to natural processes or the works of man on this or adjacent properties. In addition, changes in applicable or appropriate standards may occur, whether they result from legislation or the broadening of knowledge. Accordingly, the findings of this report may be invalidated wholly or partially by changes outside our control. Therefore, this report is subject to review and should not be relied upon after a period of three years. File No. 04786-54-01 REF. MAP i 1991 THOMAS GUIDESAN DIEQO COUNTY, CALIF. PAGE 19 - C3 NO SCALE VICINITY MAP ALTA MIRA PARK CARLSBAD, CALIFORNIA Figure 1 File No. 04786-54-01 ASSUMED CONDITIONS: Slope Height Slope Inclination Total Unit Weight of Soil Angle of Internal Friction Apparent Cohesion No Seepage Forces H = 10 feet 2:1 (Horizontal: Vertical) Y = 130 pounds per cubic foot 4> =31 degrees C = 500 pounds per square foot ANALYSIS: vH tan 6 Equation (3-3), Reference 1 C FS YH X^ = 1.56 Nrf = 11 FS = 4.23 Equation (3-2), Reference 1 Calculated Using Eq. (3-3) Determined Using Figure 10, Reference 2 Factor of Safety Calculated Using Eq. (3-2) REFERENCES (1) Janbu, N., Stability Analysis of Slopes with Dimensionless Parameters, Harvard Soil Mechanics, Series No. 46, 1954. (2) Janbu, N., Discussion of J.M. Bell, Dimensionless Parameters for Homogeneous Earth Slopes, Journal of Soil Mechanics and Foundation Design, No. SM6, November 1967. SLOPE STABILITY ANALYSIS (CUT SLOPES) ALTA MIRA PARK CARLSBAD, CALIFORNIA Figure 3a File No. 04786-54-01 ASSUMED CONDITIONS: Slope Height Slope Inclination Total Unit Weight of Soil Angle of Internal Friction Apparent Cohesion No Seepage Forces H = 10 feet 2:1 (Horizontal: Vertical) Y = 130 pounds per cubic foot 4> =31 degrees C = 150 pounds per square foot ANALYSIS: FS Nrf FS vH tan <b Equation (3-3), Reference 1 C Equation (3-2), Reference 1 Calculated Using Eq. (3-3) Determined Using Figure 10, Reference 2 Factor of Safety Calculated Using Eq. (3-2) YH = 5.21 = 20 = 2.31 REFERENCES (1)Janbu, N., Stability Analysis of Slopes with Dimensionless Parameters, Harvard Soil Mechanics, Series No. 46, 1954. (2) Janbu, N., Discussion of J.M.Bett, Dimensionless Parameters for Homogeneous Earth Slopes, Journal of Soil Mechanics and Foundation Design, No. SM6, November 1967. SLOPE STABILITY ANALYSIS (FILL SLOPES) ALTA MIRA PARK CARLSBAD, CALIFORNIA Figure 3b File No. 04786-54-01 ASSUMED CONDITIONS: Slope Height Depth of Saturation Slope Inclination Slope Angle Unit Weight of Water Total Unit Weight of Soil Angle of Internal Friction Apparent Cohesion H = Infinite Z = 3 feet 2:1 (Horizontal: Vertical) i = 26.6 degrees Yw = 62.4 pounds per cubic foot Yt = 130 pounds per cubic foot <t> =31 degrees C = 500 pounds per square foot Slope saturated to vertical depth Z below slope face. Seepage forces parallel to slope face. ANALYSIS: FS =C +) Z cos2 i tan<{> Y, Z sin i cos i 3.83 REFERENCES (1) Haefeli, R. The Stability of Slopes Acted Upon by Parallel Seepage, Proc. Second International Conference, SMFE, Rotterdam, 1948, 1, 57-62. (2) Skempton, A. W., and F. A. Delory, Stability of Natural Slopes in London Clay, Proc. Fourth International Conference, SMFE, London, 1957, 2, 378-81. SURFICIAL SLOPE STABILITY ANALYSIS (CUT SLOPES) ALTA MIRA PARK CARLSBAD, CALIFORNIA Figure 4a File No. 04786-54-01 '«*»!» I*-' ASSUMED CONDITIONS: Slope Height Depth of Saturation Slope Inclination Slope Angle Unit Weight of Water Total Unit Weight of Soil Angle of Internal Friction Apparent Cohesion H = Infinite Z = 3 feet 2:1 (Horizontal: Vertical) i = 26.6 degrees Yw = 62.4 pounds per cubic foot Yt = 130 pounds per cubic foot 4> =31 degrees C = 150 pounds per square foot Slope saturated to vertical depth Z below slope face. Seepage forces parallel to slope face. ANALYSIS: FS =+ (yf - Yw ) Z cos2 i tan<}> Yr Z sin j cos i 1.58 REFERENCES (1) Haefeli, R. The Stability of Slopes Acted Upon by Parallel Seepage, Proc. Second International Conference, SMFE, Rotterdam, 1948, 1, 57-62. (2) Skempton, A. W., and F. A. Delory, Stability of Natural Slopes in London Clay, Proc. Fourth International Conference, SMFE, London, 1957, 2, 378-81. SURFICIAL SLOPE STABILITY ANALYSIS (FILL SLOPES) ALTA MIRA PARK CARLSBAD, CALIFORNIA Figure 4b File No. 04786-54-01 WALL FOOTING CONCRETE SLAB ao'.»..*«.-. " *•: SANDS VISQUEEN - PAD GRADE £ FOOTING * WIDTH NO SCALE COLUMN FOOTING CONCRETE SLAB SANDS VISOUEEN - M^ ••$?//&(&' FOOTING WIDTH *NO SCALE * SEE REPORT FOR FOUNDATION WIDTH AND DEPTH RECOMMENDATIONS WALL / COLUMN FOOTING DIMENSION DETAIL ALTA MIRA PARK CARLSBAD, CALIFORNIA Figure 5 File No. 04786-54-01 PROPERLY RET WALL ///j^i/ ^^t ^» i 12" i *" ~~ MIN. ~~if • A ' » '—-'4 ^c>-\ ^* COMPACTED BACKFILL | ' r3" r H \ 3 ^CRUSHED ROCK 4 — FILTER FABRIC ENVELOPE OR EQUIVALENT 4" DIA. PERFORATED ABS OR ADS PIPE 1. PREFABRICATED DRAINAGE PANELS SUCH AS MIRADRAIN 7000 OR EQUIVALENT MAY BE USED IN LIEU OF PLACING GRAVEL TO A HEIGHT OF 2/3 THE TOTAL WALL HEIGHT. 2. DRAIN SHOULD BE UNIFORMLY SLOPED AND MUST LEAD TO A POSITIVE GRAVITY OUTLET OR TO A SUMP WHERE WATER CAN BE REMOVED BY PUMPING. NO SCALE RETAINING WALL DRAIN DETAIL ALTA MIRA PARK CARLSBAD, CALIFORNIA Figure 6 APPENDIX A File No. 04786-54-01 February 5, 1992 APPENDIX A FIELD INVESTIGATION The field investigation was performed on January 13 and 14, 1992, and consisted of the excavation of twenty exploratory trenches. The approximate locations of the trenches are shown on the Geologic Map, Figure 2. Trench excavations were advanced to depths ranging from 7 to 15 feet below the existing ground surface using a trackhoe equipped with a 24-inch-wide bucket. Disturbed bulk and chunk samples were retrieved at selected depths within trench excavations. The soil conditions encountered within the exploratory trenches were visually classified and logged in general accordance with the American Society for Testing and Materials (ASTM) Practice for Description and Identification of Soils (Visual-Manual Procedure D2844). Logs of the exploratory trenches are presented on Figures A-l through A-20. The logs depict the various soil types encountered and indicate the depths at which samples were obtained. FILE NO. 04786-54-01 j»»4 »W «IM> * DEPTH IN reel - n - - 2 - - 4 - ~ ~" - 6 - - 8 - - 10 - SAMPLE NO. Tl-1 Tl-2 Tl-3 3 1 g51 & 1 i 1 ( < i H 13 : j y//% 1 ^^iI '%I rrUJ 3 cra SOIL CLASS (USCS) SM SC-SM TRENCH T 1 ELEVATION 184 DATE COMPLETED 1/13/92 EQUIPMENT TRACKHOE MATERIAL DESCRIPTION rOFSOUL/DlSlUKUJiD FORMA 1 ION AL SOIL Medium dense, moist, dark brown, Clayey, Occasional trash debris / TERRACE DEPOSITS Dense, moist, mottled greenish gray and rust brown, Clayey to Silty, fine to medium-grained SANDSTONE; friable and weakly cemented. Occasional interbeds of sandy lean clay -Becomes very dense to hard and moderately cemented below 9 feet TRENCH TERMINATED AT 12 FEET o u ^S"Hips m <n ° ^L ^ - - - ~ - - - > MO >5 Q 115.5 113.4 ~ feWO •* Oo 11.4 14.9 Figure A-l, Log of Trench T 1 AMP SAMPLE SYMBOLS D... SAMPLING UNSUCCESSFUL B... STANDARD PENETRATION TEST I... DRIVE SAMPLE (UNDISTURBED) DISTURBED OR BAG SAMPLE ... CHUNK SAMPLE T. ... WATER TABLE OR SEEPAGE NOTE: THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES. FILE NO. 04786-54-01 L (••DEPTH IN FEET - fiV - 2 - - 4 - ~ ~ - 6 - - SAMPLE NO. : c : » ff 33 : HJ 1 11 (T E D Q IT0 SOIL CLASS (USCS) SM SC-SM SM TRENCH T 2 ELEVATION 159 DATE COMPLETED 1/13/92 EQUIPMENT TRACKHOE MATERIAL DESCRIPTION TOFSOIL Loose moist to wet dark brown Silty, rA fine to medium SAND with trace clay / TERRACE DEPOSITS Medium dense to dense, moist, greenish gray with rust brown mottling, interbedded Clayey to Silty, fine to medium-grained SANDSTONE: friable and weaklv cemented -Highly weathered in upper 2 feet Dense to very dense, moist, rust brown, Siltv. fine to coarse SANDSTONE with trace of clay; friable; weakly to \ moderately well cemented I TRENCH TERMINATED AT 9 FEET 3g~H y K*!* £"!?UJH0 IL v _ - ™ - ~ 1- _H'* §!L goo . >i a ^§"sSo ^oo Figure A-2, Log of Trench T 2 AMP SAMPLE SYMBOLS I... SAMPLING UNSUCCESSFUL B ... STANDARD PENETRATION TEST I... DRIVE SAMPLE (UNDISTURBED) !... DISTURBED OR BAG SAMPLE 0 ... CHUNK SAMPLE ... WATER TABLE OR SEEPAGE NOTE: THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES. FILE NO. 04786-54-01 DEPTH IN reel - n - - 2 - - A - 6 - 8 - - in - SAMPLE NO. T3-1 T3-2 [ 7/ : tt j H J \ 4l trui Q o § I SOIL CLASS (USCS) SP-SM SC-SM TRENCH T 3 ELEVATION 130 DATE COMPLETED 1/13/92 EQUIPMENT TRACKHOE MATERIAL DESCRIPTION ALLUVIUM Loose, wet, interbedded rust brown, medium SAND with some silt and dark gray, Silty, fine to medium SAND with some clay. Occasional rootlets. \ 1 to 5 feet / DELMAR FORMATION Medium dense, wet to moist, gray with rust brown mottling, Clayey, fine to medium SAND to Silty, fine to coarse SAND. Occasional white carbonaceous staining TRENCH TERMINATED AT 10 FEET •RATIONSTANCEIS/FT. )C5°5 KJ mo. a •*, - - -lENSITYC.F.)" .>£S 100.4 iu8 hQ) 2j O •Spoa 16.1 Figure A-3, Log of Trench T 3 AMP SAMPLE SYMBOLS D... SAMPLING UNSUCCESSFUL Hi ... DISTURBED OR BAG SAMPLE D ... STANDARD PENETRATION TEST • ... DRIVE SAMPLE (UNDISTURBED) 0 ... CHUNK SAMPLE I ... WATER TABLE OR SEEPAGE NOTE: THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES. FILE NO. 04786-54-01 1 DEPTH IN FEET - - 2 - - - 4 - - ft - - - 1 SAMPLE NO. T4-1 T4-2 Iaj| 88 0o o H 'wk •fjg ' *J « ' ^ ' ^, Jj ^.£ Q; UJ Q Q g SOIL CLASS (USCS) SP-SM CL SC-CL TRENCH T 4 ELEVATION 115 DATE COMPLETED 1/13/92 EQUIPMENT TRACKHOE MATERIAL DESCRIPTION ALLUVIUM Loose, moist, light brown, medium SAND with little silt and gravel; ', micaceous » 1 Very stiff, moist, irayish" brown, Sandy CLAY. Fissured \ DELMAR FORMATION Dense, damp, grayish brown, Clayey, fine- grained SANDSTONE to a hard, fine Sandv CLAYSTONE. Weathered: fractured and blocky; shiny parting surfaces; moderately well-indurated TRENCH TERMINATED AT 9 FEET |uj« ir * (o i^ H 5 ui ^ ma a ~ - — - - - ~ > i"*•>t Q 111.5 \ ~iu g in 7: §1u 21.5 Figure A-4, Log of Trench T 4 AMP SAMPLE SYMBOLS ... SAMPLING UNSUCCESSFUL D ... STANDARD PENETRATION TEST • ... DRIVE SAMPLE (UNDISTURBED) ... DISTURBED OR BAG SAMPLE Q ... CHUNK SAMPLE Z ... WATER TABLE OR SEEPAGE NOTE: THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES. FILE NO. 04786-54-011 DEPTH IN FEET - n -U - 2 - . 4 _ - 6 - - 8 SAMPLE NO. 8 o H GROUNDUATERSOIL CLASS (USCS) SM SM TRENCH T 5 ELEVATION 140 DATE COMPLETED 1/13/92 EQUIPMENT TRACKHOE MATERIAL DESCRIPTION TOPSOIL fine to medium SAND. Numerous root I fibers; porous i lliRRACE DEPOSITS Dense, damp to moist, dark reddish brown, Silty, fine to medium grained SANDSTONE with little clay. Numerous root voids to 5 feet. Weakly cemented and friable. Spotty black carbonaceous staining TRENCH TERMINATED AT 8 FEET PENETRATIONRESISTANCE(BLOWS/FT. )_ -DRY DENSITY(P.C.F.)MOISTURECONTENT (X)Figure A-5, Log of Trench T 5 AMP SAMPLE SYMBOLS Q... SAMPLING UNSUCCESSFUL B... STANDARD PENETRATION TEST I... DRIVE SAMPLE (UNDISTURBED) I ... DISTURBED OR BAG SAMPLE 0 ... CHUNK SAMPLE Z ... WATER TABLE OR SEEPAGE NOTE: THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES. FILE NO. 04786-54-01 L DEPTH IN - nu - *• - 4 - — ~ - 6 - - 8 - - - 10 - - 12 - f 14 - SAMPLE NO. T6-1 T6-2 T6-3 xliI\\\•^ 7 >Oo 1- H : ' •: il**. ff UJ O Qaa SOIL CLASS (USuS; SM SP-SM TRENCH T 6 ELEVATION 180 DATE COMPLETED 1/13/92 EQUIPMENT TRACKHOE MATERIAL DESCRIPTION TOPSOIL/DISTURBED FORMATIONAL SOIL Loose to medium dense, moist, dark reddishn brown, Silty. fine to medium SAND r with little clay / /TtRRACE DEPOSITS Dense, moist, rust brown, fine to medium- grained SANDSTONE with some silt and trace of clay. Friable and weakly cemented; localized, very dense, moderately well cemented lenses. Spotty black carbonaceous staining -Becomes greenish gray mottled and less cemented below 9 feet TRENCH TERMINATED AT 15 FEET Z QJ ~ Hiu ii Q. a w - - - - - ^H^ Q ^ a^0 123.6 117.1 ^g-eg(0 if; °| O 7.2 7.1 Figure A-6, Log of Trench T 6 ^•*K AMP SAMPLE SYMBOLS D... SAMPLING UNSUCCESSFUL C ... STANDARD PENETRATION TEST I... DRIVE SAMPLE (UNDISTURBED) ... DISTURBED OR BAG SAMPLE ... CHUNK SAMPLE ... WATER TABLE OR SEEPAGE NOTE: THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES. FILE NO. 04786-54-01 I j DEPTH IN FEET - 0 - 2 - - A - 6 - - 8 - - in - SAMPLE NO.LITHOLOQYa GROUNDUATER |i SOIL CLASS (USCS) SM SC SM TRENCH T 7 ELEVATION 160 DATE COMPLETED 1/13/92 EQUIPMENT TRACKHOE MATERIAL DESCRIPTION TOPSO1L Loose, wet, dark brown, Silty, fine to root fibers i TERRACE DEPOSITS 1 gray and rust brown, Clayey, fine to , , medium SAND ' Becomes medium dense to dense, moist, greenish gray and rust brown mottled, Silty, fine to medium-grained SANDSTONE with little clay. Weakly cemented and friable TRENCH TERMINATED AT 10 FEET PENETRATIONRESISTANCE(BLOWS/FT. )- - -DRY DENSITY(P.C.F.)MOISTURECONTENT (X)Figure A-7, Log of Trench T 7 AMP SAMPLE SYMBOLS |... SAMPLING UNSUCCESSFUL E... STANDARD PENETRATION TEST • ... DRIVE SAMPLE (UNDISTURBED) ... DISTURBED OR BAG SAMPLE 0 ... CHUNK SAMPLE JL ... WATER TABLE OR SEEPAGE NOTE: THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES. FILE NO. 04786-54-01 I f DEPTH IN - fiu . — - 2 - - - 4 - - 6 - Q- 8 SAMPLE NO. T8-1 * | \ T8-2 J / I I S c H H J fV JNDUATEO a SOIL CLASS (USC5) SM SM TRENCH T 8 ELEVATION 133 DATE COMPLETED 1/13/92 EQUIPMENT TRACKHOE MATERIAL DESCRIPTION ALLUVIUM Loose to medium dense, wet, dark brown, Siltv, fine to medium SAND with little clay -Thin gravel layer at 4.5 feet DELMAR FORMATION Medium dense to dense, moist, light brownish gray, Silty, fine to medium grained SANDSTONE with some clay. Highly weathered in upper 2 feet. Friable and weakly cemented. Occasional A rust brown mottling 1 TRENCH TERMINATED AT 9 FEET •RATIONSTANCEJS/FT. )UJHO n "• w )ENSITYC.F.)" * >£ O 119.8 gg <" mHHfgz 0 13.3 Figure A-8, Log of Trench T 8 AMP SAMPLE SYMBOLS D ... SAMPLING UNSUCCESSFUL B ... STANDARD PENETRATION TEST ... DISTURBED OR BAG SAMPLE ... CHUNK SAMPLE ... DRIVE SAMPLE (UNDISTURBED) ... WATER TABLE OR SEEPAGE NOTE: THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES. FILE NO. 04786-54-01I DEPTH IN FEET - 0 - . - 2 - - - 4 - ~ •" - 6 - - - SAMPLE NO. >O LITHOLO: auh-QROUNDbJASOIL CLASS (USCS) SM SM TRENCH T 9 ELEVATION 148 DATE COMPLETED 1/14/92 EQUIPMENT TRACKHOE MATERIAL DESCRIPTION TOPSOIL/DISTURBED FORMATIONAL SOIL to medium SAND with little clay. Numerous root fibers JLtKRACE DEPOSITS Medium dense to dense, moist, rust brown with greenish gray mottling, Silty, fine to medium-grained SANDSTONE with little clav. Weathered in upper 2 feet; becomes weakly cemented and friable below 4 feet TRENCH TERMINATED AT 9 FEET U"*1 ^\PENETRATKRESISTANC(BLOWS/FT- - - — - > Lm 828« >°-ir~Q *•*... X'MOISTURECONTENT CFigure A-9, Log of Trench T 9 AMP SAMPLE SYMBOLS D ... SAMPLING UNSUCCESSFUL C ... STANDARD PENETRATION TEST • ... DRIVE SAMPLE (UNDISTURBED) ... DISTURBED OR BAG SAMPLE ... CHUNK SAMPLE I ... WATER TABLE OR SEEPAGE NOTE: THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES. FILE NO. 04786-54-01 t DEPTH IN FEET - 0 - - 2 - - A - - ft -O - 8 - - 10 - ' SAMPLE NO. e 3 H 1 1 1 1 Vj/ SS<%: ^ ff JNDUATEOKCD I SOIL CLASS (USCS) SM SC SC SM TRENCH T 10 ELEVATION 125 DATE COMPLETED 1/14/92 EQUIPMENT TRACKHOE MATERIAL DESCRIPTION ALLUVIUM Loose, wet, dark brown, Silty, fine to medium SAND. Numerous root fibers 1 Medium dense, wet, reddish brown, Clayey, _ fin** fn medium ^ANT") Of*f*aQinnflI Qiih— « \ rounded gravels and cobbles to 4 inches / DELMAR FORMATION i Medium dense, wet, grayish brown with rust i1 brown mottling, Clayey, fine to medium \ SAND. Rapid seepage and caving into , i trench at 6 to 6.5 feet «i Becomes dense, wet, light gray and rust mottled, fine to medium grained SANDSTONE with some clay; weathered, weakly cemented and friable -Becomes light gray and fresher below 9 feet TRENCH TERMINATED AT 1 1 FEET •RATIONSTANCEIS/FT. )"" M •* U> ^ - - - - |2 >t a "1 o ^Figure A-10, Log of Trench T 10 AMP SAMPLE SYMBOLS D ... SAMPLING UNSUCCESSFUL B ... STANDARD PENETRATION TEST ... DISTURBED OR BAG SAMPLE CHUNK SAMPLE ... DRIVE SAMPLE (UNDISTURBED) ... WATER TABLE OR SEEPAGE NOTE: THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES. FILE NO. 04786-54-01 1 DEPTH IN FEET O — - 2 - - 4 - - 6 - - 8 - - in -1U SAMPLE NO.LITHOLOQYI QROUNDUATERSOIL CLASS (USCS) SM sc SP-SM TRENCH Til ELEVATION 161 DATE COMPLETED 1/14/92 EQUIPMENT TRACKHOE MATERIAL DESCRIPTION ALLUVIUM Loose to medium dense, moist to wet, dark brown and dark grayish brown, Siltv. fine to medium SAND. Numerous root fibers in upper 2 feet TERRACE DEPOSITS Medium dense, moist to wet, greenish ' medium SAND; micaceous • , „ ,'Becomes dense, moist, rust brown, fine to medium grained SANDSTONE with some •\ silt. Weakly cemented and friable r TRENCH TERMINATED AT 10 FEET PENETRATIONRESISTANCE(BLOWS/FT. )- - -DRY DENSITY(P.C.F.)MOISTURECONTENT OO^Figure A-ll, Log of Trench T 11 AMP SAMPLE SYMBOLS D... SAMPLING UNSUCCESSFUL B... STANDARD PENETRATION TEST I... DRIVE SAMPLE (UNDISTURBED) ... DISTURBED OR BAG SAMPLE ... CHUNK SAMPLE ... WATER TABLE OR SEEPAGE NOTE: THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES. FILE NO. 04786-54-01 DEPTH IN FEET - n -U _ - 2 - - 4 - _ ~. - 6 - - - 8 - - in - SAMPLE NO. T12-1 7 £ i : * 5 J 4 J ^u Q OUa SOIL CLASS (USCS) SM SM TRENCH T 12 ELEVATION 181 DATE COMPLETED 1/14/92 EQUIPMENT TRACKHOE MATERIAL DESCRIPTION TOFbUlL/UlSiUKBliD FORMATION AL SOIL Medium dense, moist, dark brown, Silty, TERRACE DEPOSITS Dense to very dense, damp to moist, rust brown, Silty, fine to medium grained SANDSTONE with little clav. Micaceous. Occasional moist, greenish gray mottled, clayey sandstone interbeds; weakly cemented and friable; localized lenses of moderate cementation TRENCH TERMINATED AT 10 FEET og~ H|£ UJ H Q jfji"on. "• ^ _ _ - ™ - - H> SSli^ .>£a 115.8 £ IH ^O 7 u 7.4 Figure A-12, Log of Trench T 12 AMP SAMPLE SYMBOLS D... SAMPLING UNSUCCESSFUL B... STANDARD PENETRATION TEST I... DRIVE SAMPLE (UNDISTURBED) ... DISTURBED OR BAG SAMPLE ... CHUNK SAMPLE f. ... WATER TABLE OR SEEPAGE NOTE: THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES. FILE NO. 04786-54-01 1 DEPTH IN FEET - 0 - — - 4 - - 6 - - 8 - - 10 - SAMPLE NO. T13-1 I £ I > t~ J • • . (T111 Q g SOIL CLASS (USCS) SM SP-SM TRENCH T13 ELEVATION 185 DATE COMPLETED 1/14/92 EQUIPMENT TRACKHOE MATERIAL DESCRIPTION TOP5U1L/U1S1UKBEJLJ FORMA I ION AL SOIL Medium dense, moist, brown, Silty, fine SAND. Porous; occasional root fibers TERRACE DEPOSITS Dense, damp to moist, greenish gray and rust brown mottled, medium-grained SANDSTONE with some silt; weakly cemented and friable; locally, mod- erately well-cemented TRENCH TERMINATED AT 1 1 FEET z ~2 o tlM g t- Ul m OT. (0 |• in ^ Q. "• ~ y ^% ill a^0 ^ uj ia Si0 *~iz o Figure A-13, Log of Trench T 13 AMP SAMPLE SYMBOLS D ... SAMPLING UNSUCCESSFUL ... DISTURBED OR BAG SAMPLE E... STANDARD PENETRATION TEST I... DRIVE SAMPLE (UNDISTURBED) 0 ... CHUNK SAMPLE JL ... WATER TABLE OR SEEPAGE NOTE: THE LOG OF SUBSURFACE CONDITIONS SHOUN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES. FILE NO. 04786-54-01 1 DEPTH IN FEET nU - 2 - - 4 - - 6 - SAMPLE NO.LITHOLOQY\GROUNDUATERSOIL CLASS <USCS) SP-SM SM-SC SM TRENCH T14 ELEVATION 163 DATE COMPLETED 1/14/92 EQUIPMENT TRACKHOE MATERIAL DESCRIPTION TOPSOIL SAND with some silt. Abundant root fibers TERRACE DEPOSITS1 Medium dense, moist, greenish gray, ' i Silty to Clayey, fine to medium- J i grained SANDSTONE: weakly cemented i '( and friable ' Becomes dense to very dense, damp to moist, greenish gray and rust brown mottled, Silty, fine to medium- grained SANDSTONE. Weakly to moderately well cemented and friable TRENCH TERMINATED AT 7 FEET PENETRATIONRESISTANCE<BLOUIS/FT. )- - -DRY DENSITY(P.C.F.)MOISTURECONTENT (X)^Figure A-14, Log of Trench T 14 AMP SAMPLE SYMBOLS D... SAMPLING UNSUCCESSFUL B ... STANDARD PENETRATION TEST I... DRIVE SAMPLE (UNDISTURBED) ... DISTURBED OR BAG SAMPLE CHUNK SAMPLE I ... WATER TABLE OR SEEPAGE NOTE: THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES. FILE NO. 04786-54-011 t DEPTH IN FEET - 0 -\J - - 4 - - 6 - 8 _O - _ in SAMPLE NO. C : h I i 4 J 1 /%£ (TU iQ —}naa SOIL CLASS (USCS) SP-SM SM SC SM TRENCH T IS ELEVATION 145 DATE COMPLETED 1/14/92 EQUIPMENT TRACKHOE MATERIAL DESCRIPTION ALLUVIUM Loose, moist to wet, grayish brown, medium SAND with little silt. •' Abundant root fibers r Loose, moist to wet, dark brown, Silty, fine to medium SAND TERRACE DKFUS1TS Medium dense, moist, rust brown, Clayey, fine to medium SAND Becomes dense to very dense, moist, rust brown with greenish gray mottling, Silty, \ tine to medium-grained oAiN_yolUlNh. Weakly cemented and friable TRENCH TERMINATED AT 10 FEET iuj": M2 '-H * IL<r 5 \ £"!£ i"5i0, "• s^ - _ — - > |2 go a. w Q Q a^eg<n 2 °z o Figure A-15, Log of Trench T 15 AMP SAMPLE SYMBOLS D ... SAMPLING UNSUCCESSFUL I] ... STANDARD PENETRATION TEST • ... DRIVE SAMPLE (UNDISTURBED) ... DISTURBED OR BAG SAMPLE ... CHUNK SAMPLE I ... WATER TABLE OR SEEPAGE NOTE: THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES. FILE NO. 04786-54-01 1 DEPTH IN FEET n -u - 2 - - - 4 - - 6 - - - 8 - - 10 - - 10 -1Z ~ SAMPLE NO. i ).f. ^i™ • I , > i ri i ii i .* i i' i i !—*• i i i 4 J 1 i ' i1 1 i rr LJNDUATEOITa * SOIL CLASS (U5C5; SM SM <sM CL TRENCH T 16 ELEVATION 134 DATE COMPLETED 1/14/92 EQUIPMENT TRACKHOE MATERIAL DESCRIPTION ALLUVIUM Loose, moist to wet, dark brown, Silty, fine to medium SAND. Abundant root "I fibers /" TERRACE DEPOSITS Medium dense, wet, rust brown, Silty, fine to medium-grained SANDSTONE with little clay. Micaceous; weakly cemented and friable. Rapid seepage r1 and minor caving from 5.5 to 8 feet ' Dense, wet to moist, mottled rust brown and greenish gray, fine to medium- grained \ SANDSTONE. Weakly cemented and friable 1 DELMAR FORMATION Very stiff to hard, moist, light gray, fine Sandy CLAYSTONE Fractured 1 and blocky with shiny parting surfaces. 1 1 Highly weathered in upper 2 feet 1 TRENCH TERMINATED AT 12 FEET 'RATIONSTANCEJS/FT. )z"3uigmQ. °- ^ - - - - - -JENSITYC.F. )" . >i(E ~O *Niu£ SfeW mH£0 t= iO Figure A-16, Log of Trench T 16 AMP SAMPLE SYMBOLS D ... SAMPLING UNSUCCESSFUL STANDARD PENETRATION TEST ... DISTURBED OR BAG SAMPLE 0 ... CHUNK SAMPLE ... DRIVE SAMPLE (UNDISTURBED) ... WATER TABLE OR SEEPAGE NOTE: THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES. FILE NO. 04786-54-01 /J%M' DEPTH IN FEET - n - 2 - - 4 - - (\o SAMPLE NO. a .ITHOUO1 y/\ KUJ1-<I | O o SOIL CLASS (USCS) SM SM TRENCH T17 ELEVATION 150 DATE COMPLETED 1/14/92 EQUIPMENT TRACKHOE MATERIAL DESCRIPTION UNSUITABLE FILL Loose, moist to dry, rust brown, Silty to Clayey, fine to medium SAND mixed with abundant trash debris (plastic, wood, shoes, brush, etc..) TERRACE DEPOSITS Dense, damp to moist, rust brown with • 1 1 1 1 * j O"1* t {" M n *j-«greeuisn gi<ty iiiuiiiiug, oiuy, mic lu medium-grained SANDSTONE with some clay. Weakly cemented and friable; black carbonaceous staining TRENCH TERMINATED AT 7 FEET 0 "^ UJ (A Q ?• UJ Mtil rl CDo. a ~ - - - si ^ • a w a Q a w = K EZ O Figure A-17, Log of Trench T 17 AMP SAMPLE SYMBOLS D... SAMPLING UNSUCCESSFUL ... DISTURBED OR BAG SAMPLE D... STANDARD PENETRATION TEST 0 ... CHUNK SAMPLE DRIVE SAMPLE (UNDISTURBED) WATER TABLE OR SEEPAGE NOTE: THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES. FILE NO. 04786-54-011 DEPTH IN FEET -fi-ll - 2 - - 4 - - 6 - - 8 - - 10 - SAMPLE NO.LITHOLOQY• ^ •QROUNDUATER |» SOIL CLASS (USCS) SM SP-SM SW SW TRENCH T18 ELEVATION 133 DATE COMPLETED 1/14/92 EQUIPMENT TRACKHOE MATERIAL DESCRIPTION TOPSOEL fine to medium SAND. Abundant rootlets / TERRACE DEPOSITS Dense, damp to moist, rust brown, medium- (-1 grained SANDSTONE with some silt. i , Weakly cemented and friable 'i ,' Dense to medium dense, moist to wet, rust brown, Gravelly, fine to coarse- grained SANDSTONE. Subrounded gravels and cobbles to 6 inches; weakly cemented n and friable. Micaceous. Rapid seepage minor caving into trench 6 to 8 feet DELMAR FORMATION Dense, wet to moist, light gray with rust brown mottling, fine to coarse- grained SANDSTONE with little clay, weakly cemented and friable TRENCH TERMINATED AT 1 1 FEET PENETRATIONRESISTANCE(BLOUS/FT. )- - - -DRY DENSITY(P.C.F. )MOISTURECONTENT (X)Figure A-18, Log of Trench T 18 AMP , SAMPLE SYMBOLS ... SAMPLING UNSUCCESSFUL U... STANDARD PENETRATION TEST •... DRIVE SAMPLE (UNDISTURBED) ... DISTURBED OR BAG SAMPLE E3 ... CHUNK SAMPLE T. ... WATER TABLE OR SEEPAGE NOTE: THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES. FILE NO. 04786-54-01 DEPTH IN FEET - 0 -u - 9 - - 4 - - 6 - - - 8 - i f\• iu - SAMPLE NO.rHOLOQYH_1 : : ;- .»•» ^ •[''•""' I lll.«l IT JNDUATEOa.o T SOIL CLASS (USCS) SM SP-SM SW SW/CL TRENCH T 19 ELEVATION 132 DATE COMPLETED 1/14/92 EQUIPMENT TRACKHOE MATERIAL DESCRIPTION TOPSOIL Loose, moist to wet, dark brown, Silty, ~\ fine to medium SAND r TERRACE DEPOSITS Medium dense to dense, moist, rust brown • and greenish gray mottled, fine to medium- ,~ , grained SANDSTONE with some silt. , i Weakly cemented and friable; micaceous 'i ' Medium dense, wet, rust brown, Gravelly, fine to coarse SANDSTONE with little clay Very weakly cemented and friable; micaceous; subrounded gravels and cobbles to 6 inches. Slow seepage into trench at 4.5 to 6.5 feet DELMAR FORMATION Interbedded, dense, moist, light gray, fine to coarse SANDSTONE with some clay and very stiff to hard, fine Sandy CLAYSTONE. Claystone is blocky with shiny parting surfaces. Sandstone is weakly cemented and friable TRENCH TERMINATED AT 10 FEET •RATIONSTANCEIS/FT. )1" u -»I" m OZ ft Jiti £ mQ. "• ^ - - - - -lENSITYC.F. )" . N.O.a~o /•s iu;5 (0 j?SM[JJgz*-ou Figure A-19, Log of Trench T 19 AMP SAMPLE SYMBOLS D ... SAMPLING UNSUCCESSFUL B ... STANDARD PENETRATION TEST • ... DRIVE SAMPLE (UNDISTURBED) I ... DISTURBED OR BAG SAMPLE 0 ... CHUNK SAMPLE I ... WATER TABLE OR SEEPAGE NOTE: THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES. FILE NO. 04786-54-01 DEPTH IN - fl -U - - 4 - - 6 - SAMPLE NO. 1 5 K // \ tr JNDUATE0g SOIL CLASS (USCS) SM SM-SC TRENCH T 20 ELEVATION 152 DATE COMPLETED 1/14/92 EQUIPMENT TRACKHOE MATERIAL DESCRIPTION TOPSOIL Loose, moist to wet, dark brown, Silty, \ u fine to medium SAND with some clay. r Numerous root fibers rtRRACE DEPOSITS Dense, damp to moist, rust brown with greenish gray mottling, Silty to Clayey, fine to medium-grained SANDSTONE. Weakly cemented and friable. White TRENCH TERMINATED AT 7 FEET •RATIONSTANCEIS/FT. )zS3iu £ mQ. "• w - - -JENSITYC.F.)Q !z 2in jjj lz£oo Figure A-20, Log of Trench T 20 AMP SAMPLE SYMBOLS D ... SAMPLING UNSUCCESSFUL E ... STANDARD PENETRATION TEST • ... DRIVE SAMPLE (UNDISTURBED) .. CHUNK SAMPLE I ... WATER TABLE OR SEEPAGEI ... DISTURBED OR BAG SAMPLE 0 ... NOTE: THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES. APPENDIX B File No. 04786-54-01 February 5, 1992 APPENDIX B LABORATORY TESTING Laboratory tests were performed in substantial accordance with the generally accepted test methods of the American Society for Testing and Materials (ASTM) or other suggested procedures. Chunk samples of formational soil material were tested for their in-place dry density, moisture content, shear strength, and consolidation characteristics. Selected bulk soil samples were tested for their maximum density and optimum moisture content, expansion and R-value characteristics, as well as pH (potential of Hydrogen) and resistivity properties, and soluble sulfate and chloride content. The results of our laboratory tests are presented on Tables B-I through B-V, and Figure B-l. In-place density and moisture characteristics are also presented on the logs of trenches, Figures A-l through A-20. File No. 04786-54-01 February 5, 1992 TABLE B-I Summary of In-Place Moisture-Density and Direct Shear Test Results Angle of Dry Moisture Unit Shear Density Content Cohesion Resistance Sample No. (pcf) (%) (psf) (degrees) Tl-2 115.5 11.4 Tl-3 113.4 14.9 T3-2 100.4 16.1 T4-2 111.5 21.5 T6-2 123.6 7.2 T6'3 H7-l 7.1 T8-2 119.8 13.3 T12-1 115.8 7.4 1,000 31 File No. 04786-54-01 February 5, 1992 TABLE B-H Summary of Laboratory Maximum Dry Density and Optimum Moisture Content Test Results ASTM D1557-78 Sample No.Description Maximum Dry Density (pcf) Optimum Moisture Content (% Dry Weight) Tl-1 Rust brown, Clayey to Silty, fine to medium SAND T3-1 Rust brown and dark gray, Silty, fine to medium SAND 129.6 128.5 10J 8.8 TABLE B-III Summary of Laboratory Expansion Index Test Results Sample No. Tl-1 T3-1 Moisture Before Test (%) 8.0 7.2 Content After Test (%) 25.6 17.7 Dry Density (pcf) 117.0 121.8 Expansion Index 60 1 File No. 04786-54-01 February 5, 1992 Table B-IV Summary of Water Soluble Sulfate, Chloride. oH and Resistivity Test Results Sample No. T13-1 pH 9.8 Minimum Resistivity (ohm-cm) 530 Water Soluble Sulfates (percent) .030 Water Soluble Chloride (percent) .030 TABLE B-V Summary of R-Value and Sand Equivalent Test Results Sample No. Location R- Sand Value Equivalent (SE) Tl-1 Proposed parking and driveway areas 4 T6-1 Proposed parking and driveway areas 30 8 19 File No. 04786-54-01 (0 ou Iu0. SAMPLE NO. T12-1 -4 18 14 161a.i lee APPLIED PRESSURE (ksf) Initial Dry Density (pcf) Initial Water Content (%) 115.8 7.4 Initial Saturation (%) Sample Saturated at (ksf) 12.4 0.5 CONSOLIDATION CURVE ALTA MIRA PARK CARLSBAD, CALIFORNIA AMP Figure B-l APPENDIX C APPENDIX C RECOMMENDED GRADING SPECIFICATIONS FOR "****" ALTA MIRA PARK CARLSBAD, CALIFORNIA File No. 04786-54-01 RECOMMENDED GRADING SPECIFICATIONS GENERAL 1.1 These Recommended Grading Specifications shall be used in conjunction with the Geotechnical Report for the project prepared by Geocon Incorporated. The recommendations contained in the text of the Geotechnical Report are a part of the earthwork and grading specifications and shall supersede the provisions contained hereinafter in the case of conflict. 1.2 Prior to the commencement of grading, a geotechnical consultant (Consultant) shall be employed for the purpose of observing earthwork procedures and testing the fills for substantial conformance with the recommendations of the Geotech- nical Report and these specifications. It will be necessary that the Consultant provide adequate testing and observation services so that he may determine that, in his opinion, the work was performed in substantial conformance with these specifications. It shall be the responsibility of the Contractor to assist the Consultant and keep him apprised of work schedules and changes so that personnel may be scheduled accordingly. 1.3 It shall be the sole responsibility of the Contractor to provide adequate equipment and methods to accomplish the work in accordance with applicable grading codes or agency ordinances, these specifications and the approved grading plans. If, in the opinion of the Consultant, unsatisfactory conditions such as questionable soil materials, poor moisture condition, inadequate compaction, adverse weather, and so forth, result in a quality of work not in conformance with these specifications, the Consultant will be empowered to reject the work and recommend to the Owner that construction be stopped until the unacceptable conditions are corrected. DEFINITIONS 2.1 Owner shall refer to the owner of the property or the entity on whose behalf the grading work is being performed and who has contracted with the Contractor to have grading performed. 2.2 Contractor shall refer to the Contractor performing the site grading work. 2.3 Civil Engineer or Engineer of Work shall refer to the California licensed Civil Engineer or consulting firm responsible for preparation of the grading plans, surveying and verifying as-graded topography. 2.4 Consultant shall refer to the soil engineering and engineering geology consulting firm retained to provide geotechnical services for the project. 2.5 Soil Engineer shall refer to a California licensed Civil Engineer retained by the Owner, who is experienced in the practice of geotechnical engineering. The Soil Engineer shall be responsible for having qualified representatives on-site to observe and test the Contractor's work for conformance with these specifications. 2.6 Engineering Geologist shall refer to a California licensed Engineering Geologist retained by the Owner to provide geologic observations and recommendations during the site grading. 2.7 Geotechnical Report shall refer to a soil report (including all addendums) which may include a geologic reconnaissance or geologic investigation that was prepared specifically for the development of the project for which these Recommended Grading Specifications are intended to apply. MATERIALS 3.1 Materials for compacted fill shall consist of any soil excavated from the cut areas or imported to the site that, in the opinion of the Consultant, is suitable for use in construction of fills. In general, fill materials can be classified as soil fills, soil-rock fills or rock fills, as defined below. 3.1.1 Soil fllls are defined as fills containing no rocks or hard lumps greater than 12 inches in maximum dimension and containing at least 40 percent by weight of material smaller than 3/4 inch in size. 3.1.2 Soil-rock fills are defined as fills containing no rocks or hard lumps larger than 4 feet in maximum dimension and containing a sufficient matrix of soil fill to allow for proper compaction of soil fill around the rock fragments or hard lumps as specified in Paragraph 6.2. Oversize rock is defined as material greater than 12 inches. 3.1.3 Rock fills are defined as fills containing no rocks or hard lumps larger than 3 feet in maximum dimension and containing little or no fines. Fines are defined as material smaller than 3/4 inch in maximum dimension. The quantity of fines shall be less than approximately 20 percent of the rock fill quantity. 3.2 Material of a perishable, spongy, or otherwise unsuitable nature as determined by the Consultant shall not be used in fills. 3.3 Materials used for fill, either imported or on-site, shall not contain hazardous materials as defined by the California Code of Regulations, Title 22, Division 4, Chapter 30, Articles 9 and 10; 40CFR; and any other applicable local, state or federal laws. The Consultant shall not be responsible for the identification or analysis of the potential presence of hazardous materials. However, if observations, odors or soil discoloration cause Consultant to suspect the presence of hazardous materials, the Consultant may request from the Owner the termination of grading operations within the affected area. Prior to resuming grading operations, the Owner shall provided a written report to the Consultant indicating that the suspected materials are not hazardous as defined by applicable laws and regulations. 3.4 The outer 15 feet of soil-rock fill slopes, measured horizontally, should be composed of properly compacted soil fill materials approved by the Consultant. Rock fill may extend to the slope face, provided that the slope is not steeper than 2:1 (horizontalrvertical) and a soil layer no thicker than 12 inches is track-walked onto the face for landscaping purposes. This procedure may be utilized, provided it is acceptable to the governing agency, Owner and Consultant. 3.5 Representative samples of soil materials to be used for fill shall be tested in the laboratory by the Consultant to determine the maximum density, optimum moisture content, and, where appropriate, shear strength, expansion, and gradation characteristics of the soil. 3.6 During grading, soil or groundwater conditions other than those identified in the Geotechnical Report may be encountered by the Contractor. The Consultant shall be notified immediately to evaluate the significance of the unanticipated condition. CLEARING AND PREPARING AREAS TO BE FILLED 4.1 Areas to be excavated and filled shall be cleared and grubbed. Clearing shall consist of complete removal above the ground surface of trees, stumps, brush, vegetation, man-made structures and similar debris. Grubbing shall consist of removal of stumps, roots, buried logs and other unsuitable material and shall be performed in areas to be graded. Roots and other projections exceeding 1-1/2 inches in diameter shall be removed to a depth of 3 feet below the surface of the ground. Borrow areas shall be grubbed to the extent necessary to provide suitable fill materials. 4.2 Any asphalt pavement material removed during clearing operations should be properly disposed at an approved off-site facility. Concrete fragments which are free of reinforcing steel may be placed in fills, provided they are placed in accordance with Section 6.2 or 6.3 of this document. 4.3 After clearing and grubbing of organic matter or other unsuitable material, loose or porous soils shall be removed to the depth recommended in the Geotechnical Report. The depth of removal and compaction shall be observed and approved by a representative of the Consultant. The exposed surface shall then be plowed or scarified to a minimum depth of 6 inches and until the surface is free from uneven features that would tend to prevent uniform compaction by the equipment to be used. 4.4 Where the slope ratio of the original ground is steeper than 6:1 (horizontahverticai), or where recommended by the Consultant, the original ground should be benched in accordance with the following illustration. TYPICAL BENCHING DETAIL FINISH GRADE FINISH SLOPE SURFACE REMOVE AS RECOMMENCED BY SOIL ENGINEER SLOPE TO BE SUCH THATSLOUGHING OR SLIDING DOES NOT OCCUR NO SCALE NOTES: (1) Key width MB" should be a minimum of 10 feet wide, or sufficiently wide to permit complete coverage with the compaction equipment used. The base of the key should be graded horizontal, or inclined slightly into the natural slope. (2) The outside of the bottom key should be below the topsoil or unsuitable surficial material and at least 2 feet into dense formational material. Where hard rock is exposed in the bottom of the key, the depth and configuration of the key may be modified as approved by the Consultant. 4.5 After areas to receive fill have been cleared, plowed or scarified, the surface should be disced or bladed by the Contractor until it is uniform and free from large clods. The area should then be moisture conditioned to achieve the proper moisture content, and compacted as recommended in Section 6.0 of these specifications. COMPACTION EQUIPMENT 5.1 Compaction of soil or soil-rock fill shall be accomplished by sheepsfoot or segmented-steel wheeled rollers, vibratory rollers, multiple-wheel pneumatic-tired rollers, or other types of acceptable compaction equipment. Equipment shall be of such a design that it will be capable of compacting the soil or soil-rock fill to the specified relative compaction at the specified moisture content. 5.2 Compaction of rock fills shall be performed in accordance with Section 6.3. 6 PLACING, SPREADING AND COMPACTION OF FILL MATERIAL 6.1 Soil fill, as defined in Paragraph 3.1.1, shall be placed by the Contractor in accordance with the following recommendations: 6.1.1 Soil fill shall be placed by the Contractor in layers that, when compacted, should generally not exceed 8 inches. Each layer shall be spread evenly and shall be thoroughly mixed during spreading to obtain uniformity of material and moisture in each layer. The entire fill shall be constructed as a unit in nearly level lifts. Rock materials greater than 12 inches in maximum dimension shall be placed in accordance with Section 6.2 or 6.3 of these specifications. 6. 1.2 In general, the soil fill shall be compacted at a moisture content at or above the optimum moisture content as determined by ASTM D 1557-78. 6.1.3 When the moisture content of soil fill is below that specified by the Consultant, water shall be added by the Contractor until the moisture content is in the range specified. 6.1.4 When the moisture content of the soil fill is above the range specified by the Consultant or too wet to achieve proper compaction, the soil fill shall be aerated by the Contractor by blading/mixing, or other satisfactory methods until the moisture content is within the range specified. 6.1.5 After each layer has been placed, mixed, and spread evenly, it shall be thoroughly compacted by the Contractor to a relative compaction of at least 90 percent. Relative compaction is defined as the ratio (expressed in percent) of the in-place dry density of the compacted fill to the maximum laboratory dry density as determined in accordance with ASTM D 1557-78. Compaction shall be continuous over the entire area, and compaction equipment shall make sufficient passes so that the specified minimum density has been achieved throughout the entire fill. 6.1.6 Soils having an Expansion Index of greater than 50 may be used in fills if placed at least 3 feet below finish pad grade and should be compacted at a moisture content generally 2 to 4 percent greater than the optimum moisture content for the material. 6.1.7 Properly compacted soil fill shall extend to the design surface of fill slopes. To achieve proper compaction, it is recommended that fill slopes be over- built by at least 3 feet and then cut to the design grade. This procedure is considered preferable to track-walking of slopes, as described in the following paragraph. 6.1.8 As an alternative to over-building of slopes, slope faces may be back-rolled with a heavy-duty loaded sheepsfoot or vibratory roller at maximum 4-foot fill height intervals. Upon completion, slopes should then be track-walked with a D-8 dozer or similar equipment, such that a dozer track covers all slope surfaces at least twice. 6.2 Soil-rock fill, as defined in Paragraph 3.1.2, shall be placed by the Contractor in accordance with the following recommendations: 6.2.1 Rocks larger than 12 inches but less than 4 feet in maximum dimension may be incorporated into the compacted soil fill, but shall be limited to the area measured 15 feet minimum horizontally from the slope face and 5 feet below finish grade or 3 feet below the deepest utility, whichever is deeper. 6.2.2 Rocks or rock fragments up to 4 feet in maximum dimension may either be individually placed or placed in windrows. Under certain conditions, rocks or rock fragments up to 10 feet in maximum dimension may be placed using similar methods. The acceptability of placing rock materials greater than 4 feet in maximum dimension shall be evaluated during grading, as specific cases arise and shall be approved by the Consultant prior to placement. 6.2.3 For individual placement, sufficient space shall be provided between rocks to allow for passage of compaction equipment. 6.2.4 For windrow placement, the rocks should be placed in trenches excavated in properly compacted soil fill. Trenches should be approximately 5 feet wide and 4 feet deep in maximum dimension. The voids around and beneath rocks should be filled with approved granular soil having a Sand Equivalent of 30 or greater and should be compacted by flooding. Windrows may also be placed utilizing an "open-face" method in lieu of the trench procedure, however, this method should first be approved by the Consultant. 6.2.5 Windrows should generally be parallel to each other and may be placed either parallel to or perpendicular to the face of the slope depending on the site geometry. The minimum horizontal spacing for windrows shall be 12 feet center-to-center with a 5-foot stagger or offset from lower courses to next overlying course. The minimum vertical spacing between windrow courses shall be 2 feet from the top of a lower windrow to the bottom of the next higher windrow. 62.6 All rock placement, fill placement and flooding of approved granular soil in the windrows must be continuously observed by the Consultant or his representative. 6.3 Rock fills, as defined in Section 3.1.3, shall be placed by the Contractor in accordance with the following recommendations: 63.1 The base of the rock fill shall be placed on a sloping surface (minimum slope of 2 percent, maximum slope of 5 percent). The surface shall slope toward suitable subdrainage outlet facilities. The rock fills shall be provided with subdrains during construction so that a hydrostatic pressure buildup does not develop. The subdrains shall be permanently connected to controlled drainage facilities to control post-construction infiltration of water. 63.2 Rock fills shall be placed in lifts not exceeding 3 feet. Placement shall be by rock trucks traversing previously placed lifts and dumping at the edge of the currently placed lift. Spreading of the rock fill shall be by dozer to facilitate seating of the rock. The rock fill shall be watered heavily during placement. Watering shall consist of water trucks traversing in front of the current rock lift face and spraying water continuously during rock placement. Compaction equipment with compactive energy comparable to or greater than that of a 20-ton steel vibratory roller or other compaction equipment providing suitable energy to achieve the required compaction or deflection as recommended in Paragraph 63.3 shall be utilized. The number of passes to be made will be determined as described in Paragraph 6.33. Once a rock fill lift has been covered with soil fill, no additional rock fill . lifts will be permitted over the soil fill. 6.33 Plate bearing tests, in accordance with ASTM D1196-64, may be performed in both the compacted soil fill and in the rock fill to aid in determining the number of passes of the compaction equipment to be performed. If performed, a minimum of three plate bearing tests shall be performed in the properly compacted soil fill (minimum relative compaction of 90 percent). Plate bearing tests shall then be performed on areas of rock fill having two passes, four passes and six passes of the compaction equipment, respectively. The number of passes required for the rock fill shall be determined by comparing the results of the plate bearing tests for the soil fill and the rock fill and by evaluating the deflection variation with number of passes. The required number of passes of the compaction equipment will be performed as necessary until the plate bearing deflections are equal to or less than that determined for the properly compacted soil fill. In no case will the required number of passes be less than two. 6.3.4 A representative of the Consultant shall be present during rock fill operations to verify that the minimum number of "passes" have been obtained, that water is being properly applied and that specified procedures are being followed. The actual number of plate bearing tests will be determined by the Consultant during grading. In general, at least one test should be performed for each approximately 5,000 to 10,000 cubic yards of rock fill placed. 63 J5 Test pits shall be excavated by the Contractor so that the Consultant can state that, in his opinion, sufficient water is present and that voids between large rocks are properly filled with smaller rock material. In-place density testing will not be required in the rock fills. 6.3.6 To reduce the potential for "piping" of fines into the rock fill from overlying soil fill material, a 2-foot layer of graded filter material shall be placed above the uppermost lift of rock filL The need to place graded filter material below the rock should be determined by the Consultant prior to commencing grading. The gradation of the graded filter material will be determined at the time the rock fill is being excavated. Materials typical of the rock fill should be submitted to the Consultant in a timely manner, to allow design of the graded filter prior to the commencement of rock fill placement. 6.3.7 All rock fill placement shall be continuously observed during placement by representatives of the Consultant. OBSERVATION AND TESTING 7.1 The Consultant shall be the Owners representative to observe and perform tests during clearing, grubbing, filling and compaction operations. In general, no more than 2 feet in vertical elevation of soil or soil-rock fill shall be placed without at least one field density test being performed within that interval. In addition, a minimum of one field density test shall be performed for every 2,000 cubic yards of soil or soil-rock fill placed and compacted. 7.2 The Consultant shall perform random field density tests of the compacted soil or soil-rock fill to provide a basis for expressing an opinion as to whether the fill material is compacted as specified. Density tests shall be performed in the compacted materials below any disturbed surface. When these tests indicate that the density of any layer of fill or portion thereof is below that specified, the particular layer or areas represented by the test shall be reworked until the specified density has been achieved. 7.3 During placement of rock fill, the Consultant shall verify that the minimum number of passes have been obtained per the criteria discussed in Section 6.3.3. The Consultant shall request the excavation of observation pits and may perform plate bearing tests on the placed rock fills. The observation pits will be excavated to provide a basis for expressing an opinion as to whether the rock fill is properly seated and sufficient moisture has been applied to the material. If performed, plate bearing tests will be performed randomly on the surface of the most-recentiy placed lift. Plate bearing tests will be performed to provide a basis for expressing an opinion as to whether the rock fill is adequately seated. The maximum deflection in the rock fill determined in Section 6.3.3 shall be less than the maximum deflection of the properly compacted soil fill. When any of the above criteria indicate that a layer of rock fill or any portion thereof is below that specified, the affected layer or area shall be reworked until the rock fill has been adequately seated and sufficient moisture applied. 7.4 A settlement monitoring program designed by the Consultant may be conducted in areas of rock fill placement. The specific design of the monitoring program shall be as recommended in the Conclusions and Recommendations section of the project Geotechnical Report or in the final report of testing and observation services performed during grading. 7.5 The Consultant shall observe the placement of subdrains, to verify that the drainage devices have been placed and constructed in substantial conformance with project specifications. 7.6 Testing procedures shall conform to the following Standards as appropriate: 7.6.1 Soil and Soil-Rock Fills: 7.6.1.1 Field Density Test, ASTM D1556-82, Density of Soil In-Place By the Sand-Cone Method. 7.6.1.2 Field Density Test, Nuclear Method, ASTM D2922-81, Density of Soil and Soil-Aggregate In-Place by Nuclear Methods (Shallow Depth). 7.6.13 Laboratory Compaction Test, ASTM D1557-78, Moisture-Density Relations of Soils and Soil-Aggregate Mixtures Using 10-Pound Hammer and 18-Inch Drop. 7.6.1 A Expansion Index Test, Uniform Building Code Standard 29-2, Expansion Index Test. 7.6.2 Rock Fills: 7.6.2.1 Field Plate Bearing Test, ASTM Dl 196-64 (Reapproved 1977) Standard Method for Nonrepresentative Static Plate Load Tests of Soils and Flexible Pavement Components, For Use in Evaluation and Design of Airport and Highway Pavements. 8 PROTECTION OF WORK 8.1 During construction, the Contractor shall properly grade all excavated surfaces to provide positive drainage and prevent ponding of water. Drainage of surface water shall be controlled to avoid damage to adjoining properties or to finished work on the site. The Contractor shall take remedial measures to prevent erosion of freshly graded areas until such time as permanent drainage and erosion control features have been installed. Areas subjected to erosion or sedimentation shall be properly prepared in accordance with the Specifications prior to placing additional fill or structures. 8.2 After completion of grading as observed and tested by the Consultant, no further excavation or filling shall be conducted except in conjunction with the services of the Consultant. CERTIFICATIONS AND FINAL REPORTS 9.1 Upon completion of the work, Contractor shall furnish Owner a certification by the Civil Engineer stating that the lots and/or building pads are graded to within 0.1 foot vertically of elevations shown on the grading plan and that all tops and toes of slopes are within 0.5 foot horizontally of the positions shown on the grading plans. After installation of a section of subdrain, the project Civil Engineer should survey its location and prepare an as-built plan of the subdrain location. The project Civil Engineer should verify the proper outlet for the subdrains and the Contractor should ensure that the drain system is free of obstructions. 9.2 The Owner is responsible for furnishing a final as-graded soil and geologic report satisfactory to the appropriate governing or accepting agencies. The as-graded report should be prepared and signed by a California licensed Civil Engineer experienced in geotechnical engineering and by a California Certified Engineering Geologist, indicating that the geotechnical aspects of the grading were performed in substantial conformance with the Specifications or approved changes to the Specifications. Geocon Incorporated Form. Revision date: 06/04/90 AGRONOMIC REPORT SOIL AND PLANT LABORATORY, INC. Orange Office Lab No. 51760 February 6, 1992 The Dike Partnership One Venture, Suite 100 Irvine, CA 92718 Attn: Jim Ridge ALTA MIRA PARK - CARLSBAD Following is a report on our inspection and soil sampling of the above site on 1-22-91. Composite surface soil samples were collected from the nine general areas designated on the enclosed aerial photo. Also included are agricultural suitability and soil fertility data on a subsoil sample received from Geocon Incorporated that represents the terrace deposits anticipated at final elevations throughout the majority of the site. General Inspection The reddish brown to brown colored surface soil varies from loamy sand at locations 1 and 5 to sandy loam in texture at locations 6, 7 and 9. The location 1 soil area had not been planted recently, locations 1, 3 and 6 represent the ridge areas, locations 2, 4 and 5 the lower areas, location 9 a slope, and location 7 and 8 the upper portion. Based on the sample received the subsoil is also loamy sand to sandy loam in texture. SOIL ANALYSIS Surface Soil Soil reaction is slightly alkaline at location 2. Slightly acid at locations 3, 5 and 6 and slightly to moderately acid in remaining areas sampled with lime content low throughout. With the exception of location 6, which would restrict growth of salt sensitive plants, salinity (ECe) levels are satisfactorily low throughout. Based on the SAR values soluble sodium is adequately balanced by calcium and magnesium in all nine surface soil areas sampled. In summary, the location 6 soil area is slightly saline with remaining areas non-saline and all areas non-sodic in nature. In addition, boron concentrations which are adequate for nutritional purposes are well below the toxic range and constitute no hazard to plant P.O. Box 6566, Orange, California 92613-6566 / (714) 282-8777 FAX (714) 282-8575 P.O. Box 153, Santa Clara, California 95052-0153 / (408) 727-0330 FAX (408) 727-5125 P.O. Box 1648, Bellevue, Washington 98009-1648 / (206) 746-6665 FAX (206) 562-9531 Page 2 Dike Partnership February 6, 1992 P.O. Box 6566, Orange, California 92613-6566/(714) 282-8777 FAX (714) 282-8575 P.O. Box 153, Santa Clara. California 95052-0153/(408) 727-0330 FAX (408) 727-5125 P.O. Box 1648 Bellevue. Washington 98009-1648^(206) 746-6665 FAX (206) 562-9531 growth. Available nitrogen is moderately low to low with locations 2,3,6 and 8 optimum at locations 1, 4, 7 and 9 and fairly high at location 5. Phosphorous, which is generally fairly high to high varies from high optimum at location 5 to high at location 2. Potassium, which is also generally fairly high varies from high optimum at location 2 to high at location 4. Calcium and magnesium levels are satisfactory throughout. The unusually high surface soil, phosphorus and potassium levels indicate that substantial quantities of complete chemical fertilizers and/or manures had been applied in the past to all nine areas sampled. However, it should be noted that this has not resulted in excessively high surface soluble salts. Subsoil The subsoil zone represented by the sample received is neutral in reaction and low in lime content. The salinity (ECe) level would restrict growth of many plants and based on the SAR value soluble sodium would adversely effect both soil structure and growth of sodium sensitive plants. In summary, the subsoil zone represented by the sample received is fairly saline and moderately sodic in nature. In addition, the boron concentration is slightly but not excessively high for satisfactory growth of most landscape plants. The soil fertility data show available nitrogen and potassium slightly low with phosphorus low. Calcium is slightly low with magnesium well supplied. Recommendations As previously noted, based on the sample received the subsoil is undesirably high in soluble salts. However, there are no significant chemical problems in the nine surface soil areas sampled. If feasible, the surface soil in both cut and fill areas should be stockpiled during grading operations. If this approach can be employed, we recommend the following. The surface soil in both cut and fill areas should be removed to a minimum 18" depth and stockpiled for future use. Following rough grading the stockpile soil should be used for surface fill to the 18" depth in all areas to be landscaped again in both cut and fill areas. i£ and P.O. Box 6566, Orange, California 92613-6566/(714) 282-8777 FAX (714) 282-8575 P.O. Box 153, Santa Clara, California 95052-0153/(408) 727-0330 FAX (408) 727-5125 RO. Box 1648 Bellevue, Washington 98009-1648/(206) 746-6665 FAX (206) 562-9531 Page 3 Dike Partnership February 7, 1992 The following preplant amendment and post plant maintenance recommendations are based on using the current surface soil in all areas to be landscaped. For turf and ground cover planting the following amendments should be uniformly broadcast and thoroughly incorporated to a depth of 4- 6" by means of rototiller or equal. AM'T/1000 SO. FT. 4 cu. yds. nitrogen stabilized organic amendment derived from redwood, fir or cedar sawdust 5 Ibs. ammonium sulfate The planting pits for container grown trees and shrubs should be excavated twice the diameter and twice the depths of the root ball. On-site surface soil should be used without amending for backfill to the depths of the root ball. The backfill mix for use around the root ball should be prepared as follows: 6 parts by volume on-site surface soil 4 parts by volume nitrogen stabilized organic amendment 1 Ib. ammonium sulfate per cu. yd. of mix 2 Ibs. iron sulfate per cu. yd. of mix The above material should be thoroughly blended at central on-site locations prior to use for backfill purposes. Also, the iron sulfate should not contact cement surfaces since severe staining could occur. Since both phosphorus and potassium are fairly high to high a nitrogen-only maintenance fertilizer program can be employed for at least the first two years. Beginning approximately 30 days after planting ammonium nitrate should be applied at the rate of 3 Ibs. per 1000 sq. ft. on a monthly basis. When plants have become well established the frequency of fertilizer applications can be decreased. If unamended soil areas are to be hydroseeded, the following material should be included in the hydromulch formula: iC cwu ^K^attt ^taoo/iQto/iii, ^cic. p° B°X 6se6. °™a°- CM°'™ saiwswi™) 232-3777 FAX (714) 282-8575 P.O. Box 153, Santa Clara, California 95052-01537(408) 727-0330 FAX (408) 727-5125 RO. Box 1648 Bellevue, Washington 98009-16487(206) 746-6665 page 4 FAX ,206) 562-9531 Dike Partnership February 7, 1992 AM'T/ACRE 200 Ibs. ammonium nitrate 300 Ibs. Ureaform 38-0-0 (with 287% insoluble nitrogen) Beginning approximately 60 days after planting the maintenance fertilizer program outlined for general landscape areas can also be employed in the hydroseeded portions. Please call if^you have any questions. 7^)U/l2^ fORRES1: FF:he P.O. Box 6566, Orange, California 92613 | ^14) 282-8777 i-.. . (714)282-8575 P.O. Box 153, Santa Clara, California 95052-0153/(408) 727-0330 FAX (408) 727-5125 P.O. Box 1648 Bellevue, Washington 98009-1648/(206) 746-6665 FAX (206) 562-9531 Dike Partnership One Venture, Suite 100 Irvine, CA 92718 Attn: Jim Ridge SOIL FERTILITY AND AGRICULTURAL SUITABILITY (A04) Orange Office Lab No. 51760 February 7, 1992 Alta Mira Park, Carlsbad soil sample taken 1-23-92 j Saturation Extract Values Sam Half Parts Per Million Dry Soil 1 pie Sat. | N03-N ft % 1 1 11 16 2 12 5 3 13 9 4 13 34 5 11 278 6 14 12 7 14 27 8 13 3 9 14 19 Half Saturation % (1) Location 1 0-12" (2) Location 2 0-12" (3) Location 3 0-12" (4) Location 4 0-12" (5) Location 5 0-12" (6) Location 6 0-12" (7) Location 7 0-12" (8) Location 8 0-12" (9) Location 9 0-12" NH4-N 11 7 8 6 7 6 12 7 7 P04-P K 88 250 138 240 87 460 103 420 61 1260 113 320 119 420 83 310 85 330 Ca 670 960 670 1020 4220 940 930 730 560 -approx. field moisture SAR Mg 1 1 168 323 199 195 920 192 213 213 115 capacity. pH JECe 1 5.2 1.1 7.2 0.5 6.6 0.5 5.9 3.1 6.2 1.1 6.0 4.0 5.4 2.0 5.3 1.9 5.1 1.8 Salinity = Ca Mg Me/1 Me/1 3.7 2.1 1.4 0.8 1.3 0.9 14.4 7.4 3.5 1.8 15.1 7.8 7.0 3.8 5.7 4.0 5.7 3.1 ECe (mmhos/cm Na Me/1 4.7 2.2 1.1 10.3 3.7 8.2 8.3 8.5 5.8 at 25 K Me/1 1.1 0.4 1.9 3.6 1.6 6.8 2.0 1.8 3.1 B | SAR QUAL PPM 1 1 0.49 0.65 0.48 0.67 0.43 0.50 0.62 0.50 0.36 LIME 2.8 NONE 2.1 NONE 1.0 NONE 3.1 NONE 2.3 NONE 2.4 NONE 3.6 NONE 3.9 NONE 2.8 NONE 0 0 0 0 0 2 0 0 0 degrees C.) . - Sodium Adsorption Ratio. Dike Partnership One Venture, Suite 100 Irvine, CA 92718 Attn: Jim Ridge P.O. Box 6566, Orange, California 92613 " 14) 282-8777 r. v/14) 282-8575 P.O. Box 153, Santa Clara, California 95052-0153/(408) 727-0330 FAX (408) 727-5125 P.O. Box 1648 Bellevue, Washington 98009-1648/(206) 746-6665 FAX (206) 562-9531 SOIL FERTILITY AND AGRICULTURAL SUITABILITY Orange Office (A04) Lab No. 51760 February 7, 1992 Alta Mira Park, Carlsbad soil sample taken 1-23-92 Saturation Extract Values Sam pie # 1 Half Sat. 12 Parts Per Milli 1 N03-N NH4-N P04-P 1 21 3 3 on Dry K 80 Soil. Ca 580 Mg I . 1 639 1 pH |ECe 1 Ca Me/1 Mg Me/1 Na Me/1 K B | SAR Me/1 PPM | ! Location QUAL LIME Half Saturation %-approx. field moisture capacity. Salinity = ECe (mmhos/cm at 25 degrees C.). SAR - Sodium Adsorption Ratio. (1) Subsoil TRAFFIC STUDY O'ROURKE ENGINEERING LETTER OF TRANSMITTAL DATE: Mr. Michael W. NG, P.E. TO: 5650 El Camino Real JOB # TR02922. Suite 200 Carlsbad, CA 92008 ATTN: Mr. Michael W. NG, P.E.2011 Palomar Airport Rd. Suite 109 Carlsbad California 92009 6194316763 THESE ARE TRANSMITTED VIA Hand Carried FAX: 619 431 0672 FOR APPROVAL FOR YOUR USE AS REQUESTED X FOR REVIEW AND COMMENT COPIES ' 1 DESCRIPTION Traffic Impact Analysis for Porposed Alta Mira Park REMARKS: SIGNED O'Rourke Engineering Carlsbad • Ontario • Tustin 0 ' R0URKE ENGINEERING March 9, 1992 Mr. Michael w. NG, P.E. 5650 El Camino Real Suite 200 Carlsbad, CA 92008 \Enclosed' is the Traffic Impact Analysis Report on the proposed recreational park on Hidden Valley Road in the City of Carlsbad. 2oiiPaiomarAirPortRd. If there are any questions or comments please call me at (619) suite 109 431-6763. Carlsbad California 92009 6194316763 VerV truly yours, ™" FAX: 619 431 0672 O'Rourke Engineering Susan E. O'Rourke, P.E. President Carlsbad • Ontario • Tustin 0 ' R 0 U R K E ENGINEERING TRAFFIC IMPACT ANALYSIS FOR ALTA MIRA PARK CITY OF CARLSBAD \ 2011 Palomar Airport Rd. Suite 109 Carlsbad California 92009 619 431 6763 FAX: 619 431 0672 INTRODUCTION O'Rourke Engineering was retained by Crosby, Mead, Benton & Associates to prepare the traffic impact analysis for Alta Mira Park in the City of Carlsbad. Alta Mira Park is located east of 1-5 between Palomar Airport Road and Poinsettia Lane. The park site is bounded on the west by Paseo Del Norte, Hidden Valley Road on the east and undeveloped lands on the north and south boundary. The project location is shown as Attachment A. The park will provide recreational facilities at a community park level for the City of Carlsbad. The facilities and improvements will include tennis courts, ballfield, soccer complexes and playground areas along with the attendant parking. The park site contains approximately 42 acres. The traffic impact analysis addresses the impact of the park traffic and explores access and circulation associated with the site. Steps in the analysis include an overview of existing roadways and future roadways; assessment of project impacts on existing conditions and recommendations to mitigate impacts if necessary. The steps in the analysis and the results are discussed herein. Carlsbad • Ontario • Tuson PROJECT DESCRIPTION Alta Mira Park will provided a community park for Carlsbad within the Zone 20 Specific Plan area. The park site encompasses approximately 42 acres. The recreational facilities and improvements planned for Alta Mira Park include: Tennis Courts Primary/Secondary Fields Adult Soccer Field Enclosed Soccer Field Basketball Courts Sand Volleyball Court Tot Lots Horseshoe Pits Batting Cages Golf Tee Cage Stage Band Area Picnic Areas Tennis Clubhouse Restrooms/Snack Bar Gymnasium Maintenance Building/Yard 335 Parking spaces The site plan for the proposed improvements is provided as Attachment B. EXISTING/FUTURE ROADWAY CONDITIONS Existing conditions effecting the project were explored in terms of existing roadway geometries and existing traffic volumes. Each roadway is discussed below with the existing and future lane geometries and traffic volumes highlighted. Roadway Geometries \ Existing' roadway geometries were surveyed surrounding the proposed park site. Access to the site will be provided from two streets. These streets are Paseo Del Norte and Hidden Valley Road. Paseo Del Norte contains two north and southbound traffic lanes from Palomar Airport Road to Sea Gate Drive and one north and southbound traffic lane from Sea Gate Drive to Poinsettia Lane, along with a center two-way turn lane, bike lanes and on-street parking on both sides of the street from Palomar Airport Road to Poinsettia Lane. Currently, this roadway carries 7,900 ADT north of Poinsettia Lane based on a 1990 count by the City of Carlsbad. The street is classified as a four-lane secondary arterial north of Sea Gate Road and two lane secondary arterial south to Poinsettia Lane. Future traffic volumes are expected to be in the 7,600 to 10,200 ADT range. Hidden Valley Road does not exist in the field. It is proposed to be a two lane collector street between Palomar Airport Road and Camino De Las Ondas. The roadway geometries will include within a 68' ROW, a north and southbound traffic lane, center two-way 'left turn lane and bike lanes on both sides of the street. Based on the Composite Land Use Map of Zone 20 SPA dated March 1989, it is estimated that 520 residential units would access Hidden Valley Road. With an average of 10 trips per unit and a relatively equal north to south split, Hidden Valley Road will have an average daily traffic volume of approximately 2600 vehicles. Camino De Las Ondas will provide the southern connection to Hidden Valley Road. The roadway is a two lane road. It is expected to remain a two lane road. Attachment C exhibits the proposed roadway geometries and future PM peak hour traffic volumes around the park, as stated in the Traffic Analysis for the Zone 20 Specific Plan Area. PROJECT IMPACTS Park Site Trip Generation Based on a 50 vehicle per acre rate, as stated in the San Diego Traffic Generators Manual, January 1990, the Average Week Day Traffic (AWDT) for the park site is estimated to be 2,100 vehicles. Based on the same manual, the AM peak hour will generate 4 percent of the AWDT, while the PM peak hour generates 8 percent of the AWDT. The AM peak hour and PM peak hour will be 84 and 168 vehicles, respectively. Thus, the project trips need to be assimilated into the adjoining transportation network. Roadway Access Access to the park will be provided onto Hidden Valley Road. The entire 2,100 vehicles per day will access the site via Hidden Valley Road. These trips will be distributed from Hidden Valley Road to the north onto Palomar Airport Road and to the south via Camino De Las Ondas to Paseo Del Norte and College Boulevard. Attachments D and E illustrate the daily percent assignment and the PM peak hour trip assignment, of trips with a single access onto Hidden Valley Road, respectively. The roadway geometries proposed for Hidden Valley Road will provide sufficient capacity to accommodate the additional park traffic. A left turn lane should be 'striped out of the two way left turn lane at the northbound park entrance on Hidden Valley Road. Consideration has been given to vehicular access from Paseo Del Norte. If vehicular access were provided directly on Paseo De-1 Norte, approximately 50% of all traffic generated at the park would use this access. With Paseo Del Norte as an access route to the park site, several modifications to the existing roadway would be necessary. These modifications include removing some on-street parking along Paseo Del Norte. In addition, the internal street from the park connecting to Paseo Del Norte would need to traverse a 40 foot slope and align with Caminito Estrada. It is unlikely that the intersection of the park access with Paseo Del Norte would have sufficient traffic to meet Caltrans warrants for signalization. Attachments F and G illustrate the daily percent assignment and the PM peak hour trip assignment, respectively, of trips on the network assuming both access points are in use. ROADWAY NEEDS The proposed park site and improvements do not create a major traffic impact on the adjoining external transportation system. Based on a review of the Zone 20 Specific Plan Area Traffic Report Year 2010 Conditions, Palomar Airport Road, College Boulevard, and Poinsettia Lane have the capacity to handle the traffic generated by the park. The following table summarizes the volume to capacity ratios associated with the increase of park traffic and the corresponding level of service. The PM peak hour traffic was used for the analysis, consistent with zone 20 analysis. No significant demands are placed on the roadway network as a result of the park activities. No improvements to the external network are required if the recommendations presented as Attachment C from the Zone 20 Specific Plan Area Report are constructed. CONCLUSION The Alta Mira Park is an exciting addition to the City of Carlsbad park system. The park will allow for greater participation for all age groups with passive and active recreational facilities. \ With the improvements recommended above, the project impacts will be mitigated, and an efficient roadway network will be in place to serve the park. \PM Peak Hour LEVEL OF SERVICE (LOS) Access to Hidden Valley Road Only Existing Future Roadway Volume Caoacitv V/C LOS Volume Park Total Capacity V/C LOS Palonar Airport Road From: Paseo Del Norte To: Hidden Frora: To: • Frora: To: Hidden Valley Road Eastbound Westbound Valley Road Palomar Airport Road Park Entrance Northbound Southbound Park Entrance Poinsetta Lane Northbound Southbound 1132 5400 0.21 1924 3600 0.53 Not Not Not Not A A Constructed Constructed Constructed Constructed 1544 2283 71 165 198 85 8 8 25 25 59 59 1552 2291 96 191 257 144 5400 5400 3600 3600 3600 3600 0 0 0 0 0 0 .29 .42 .03 .05 .07 .04 A A A A A A Paseo Del Norte From: To: Palomar. Airport Road Caraino De Las Ondas Northbound Southbound 582 3600 606 3600 0.16 0.17 A A 531 571 13 13 544 584 3600 3600 0 0 .15 .16 A A V/C : Volume/Capacity \PM Peak Hour LEVa OF SERVICE (LOS) Access to Hidden Valley Road and Paseo Del Norte Existing Roadway Volume Capacity V/C LOS Volume Park Future Total Capacity V/C LOS Palomar Airport Road From: Paseo Del Norte To: Hidden From: To: From: •To: Hidden Valley Road Eastbound Westbound Valley Road Paloraar Airport Road Park Entrance Northbound Southbound Park Entrance Poinsetta Lane Northbound Southbound 1132 5400 0.21 A 1924 3600 0.53 A Not Not Not Not Constructed Constructed Constructed Constructed 1544 2283 71 166 198 85 4 13 13 4 29 29 1548 2296 84 170 227 114 5400 5400 3600 3600 3600 3600 0 0 0 0 0 0 .29 .43 .02 .05 .06 .03 A A A A A A Paseo Del Norte From: From: To: Palomar Airport Road Park Entrance Northbound Southbound Park Entrance Poinsetta Lane Northbound Southbound 582 3600 606 3600 369 1800 282 1800 0.16 A 0.17 A 0.21 A 0.16 A 531 571 426 319 17 25 25 25 548 596 451 344 3600 3600 0 0 .15 .17 1800 0.25 1800 0.19 A A A A V/C = Volume/Capacity NTS PARK SITE O'ROURKE ENGINEERING ATTACHMENT A PROJECT LOCATION MAP ALT A MIRA PARK ALTA MIRA PARK CITY PROPOSED SITE PLAN O'ROURKE ENGINEERING ATTACHMENT B PROPOSED SITE PLAN ALTA MIRA PARK PARK SITE O'ROURKE ENGINEERING LEGEND: 6P - 6 LANE ARTERIAL 4M -4 LANE ARTERIAL 4SA - 4 LANE SECONDARY ARTERIAL 2 LANE SECONDARY ARTERIAL 2 LANE COLLECTOR (XX) - AVERAGE DAILY TRAFFIC XX - PM PEAK HOUR TRAFFIC 2SA - — 2C - ATTACHMENT C ROADWAY GEOMETRICS & FUTURE TRAFFIC VOLUMES ALTA MIRA PARK ( r O'ROURKE ENGINEERING ATTACHMENT D TRIP ASSIGNMENT PERCENT SCENARIO 1: ACCESS TO HIDDEN VALLEY ROAD ONLY ALTA MIRA PARK v NTScm O'ROURKE ENGINEERING ATTACHMENT E PROJECT TRIP ASSIGNMENT PM PEAK HOUR SCENARIO 1: ACCESS TO HIDDEN VALLEY ROAD ONLY ALTA MIRA PARK | O'ROURKE ENGINEERING ATTACHMENT F TRIP ASSIGNMENT PERCENT SCENARIO 2: ACCESS TO PASEO DEL NORTE & HIDDEN VALLEY ROAD ALTAMIRAPARK I O'ROURKE ENGINEERING ATTACHMENT G PROJECT TRIP ASSIGNMENT PM PEAK HOUR SCENARIO 2: ACCESS TO PASEO DEL NORTE & HIDDEN VALLEY ROAD ALTA MIRA PARK WATER DEMAND ANALYSIS ALTA MIRA PARK PRELIMINARY IRRIGATION WATER PROJECTIONS March 24. 1992 INTRODUCTION The purpose of this document is to estimate the site water requirements for Atta Mira Park located in Carlsbad, California. All water projections are based on 3 schematic design alternatives and anticipated area's of various turfgrasses and plantings determined by The Dike Partnership. IRRIGATION WATER PROJECTIONS Preliminary estimates of irrigation water requirements were prepared utilizing schematic design information provided by The Dike Partnership. Acreage for each area have been derived from planimeter take-offs by ACI. Preliminary irrigation water projections and total season requirements for each of the 3 design alternatives are summarized on the following page. Irrigated areas within each design alternative are identified by anticipated allocation of landscape approach, ie: turfgrass at playing fields, turfgrass at passive fields, and ornamental/desert planting at planting areas. Total season requirements in acre ft. and peak season flow demands in gallons per minute are also shown on the following summary page. DETAILED MONTHLY PROJECTIONS Each specific area and individual landscape approach within each area has been evaluated for it's estimated water requirements. Each landscape approach is indicated and reflected in total square feet. The application rate for each month is calculated utilizing the average reference evapo- transpiration rate (ETo) published for the area. Each landscape approach was then assigned a crop coefficient utilizing data applicable to the area. Additionally, each resulting application rate was adjusted for an average irrigation system water distribution efficiency of 65%. Peak flow demands each month are based on a calculated watering schedule of six (6) hours per day. Maximizing application efficiencies necessitates irrigation to occur during the hours of 10:00 PM and 6:00 AM. The peak (summertime) daily flow rates have been indicated for a six (6) hour watering "window." This will allow an additional two (2) hours each day for minor adjustment to the irrigation program. Peak flow demands each month are also based on a calculated watering schedule of six (6) days per week. From time to time, repairs or maintenance is required to the irrigation system. This work cannot always be accomplished during a single day. Consequently, portions of the irrigation system may not be able to be operated within the normal irrigation schedule. In addition, not all seasons are consistent; one summer may be particularly more windy or hotter than others. To allow for these factors, it is necessary to allow peak weekly irrigation volumes to be applied in (6) days per week. This provides the seventh day for use as a "catch-up" day, to make up for time lost to repairs, to apply additional seasonal demands, or to reduce daily irrigation watering time. o ALTA NIRA PARK PRELIMINARY IRRIGATION WATER PROJECTIONS TOTAL SEASON REQUIREMENTS AMD PEAK FLOW MARCH 24, 1992 mmmmi Area Description Total Area (Acre) Irrigated Area (Acre) Total Season Req. (Ac. Ft.) Peak Season Flow(GPM) ALTERNATIVE "A" PLAYING FIELDS Turfgrass PASSIVE FIELDS Turfgrass PLANTING AREAS Ornamental/Desert Planting ALTERNATIVE "A" TOTALS 8.17 9.29 3.75 21.21 8.17 9.29 3.75 21.21 32.0 36.2 5.1 73.3 138 157 22 317 ALTERNATIVE "B" PLAYING FIELDS Turfgrass PASSIVE FIELDS Turfgrass PLANTING AREAS Ornamental/Desert Planting ALTERNATIVE "B" TOTALS 9.41 7.30 4.23 20.94 9.41 7.30 4.23 20.94 36.9 28.4 5.8 71.1 159 123 25 308 ALTERNATIVE "C" PLAYING FIELDS Turfgrass PASSIVE FIELDS Turfgrass PLANTING AREAS Ornamental/Desert Planting ALTERNATIVE "C" TOTALS 11.57 6.91 3.75 22.23 11.57 6.91 3.75 22.23 45.4 26.9 5.1 77.4 196 117 22 335 o ALTA MXRA PARK PRELIMINARY IRRIGATION WATER PROJECTIONS MONTHLY REQUIREMENTS AND PEAK FLOW FEBRUARY 27, 1992 Area Description Irrigated Area Month (Square Foot) ALTERNATIVE "A" PLAYING FIELDS Turf grass 355885 Jan. Feb. Mar. Apr. May. Jun. Jul. Aug. Sep. Oct. Nov. Dec. Sub Total PASSIVE FIELDS Turf grass 404672 Jan. Feb. Mar. Apr. May. Jun. Jul. Aug. Sep. Oct. Nov. Dec. Application Rate 2.02 2.43 4.21 4.40 5.60 5.15 6.20 5.83 4.12 2.97 2.31 1.83 47.07 1.97 2.38 4.15 4.40 5.60 5.15 6.20 5.83 4.12 2.91 2.26 1.79 Monthly Req. (Gallons) 447117 539520 934677 975904 1241679 1142877 1375463 1292360 913022 659413 512337 406470 10440840 497312 599860 1045656 1109687 1411897 1299551 1564021 1469526 1038185 733162 570464 452102 Peak Flow (GPM) 48 58 100 104 133 122 147 138 98 71 55 43 53 64 112 119 151 139 167 157 111 78 61 48 Sub Total 46.75 11791424 o Area Description Irrigated Area (Square Foot) PLANTING AREAS Ornamental/Desert Planting 163350 Month Jan. Fab. Mar. Apr. May. Jun. Jul. Aug. Sep. Oct. Nov. Dec. Application Rat* 0.69 0.83 1.45 1.54 1.96 1.80 2.17 2.04 1.44 1.02 0.79 0.63 Monthly Req. (Gallon*) 70261 84749 147731 156778 199474 183602 220966 207616 146676 103582 80596 63873 Peak Flow (GPM) 8 9 16 17 21 20 24 22 16 11 9 7 Sub Total 16.36 1665904 ALTBKNAXXVB "A" TOTALS Combined Grass & Plant Mixes 923908 Jan. Feb. Mar. Apr. May. Jun. Jul. Aug. Sep. Oct. Nov. Dec. 1014690 1224129 2128064 2242369 2853051 2626030 3160450 2969502 2097883 1496157 1163396 922446 108 131 228 240 305 281 338 317 224 160 124 99 Total (Sq. Ft. / Gal.) Total (Acres / Ac. Ft.) 923908 21.21 23898167 73.3 o f) Area Description Irrigated Area Month (Square Foot) ALTERNATIVE "B" PLAYING FIELDS Turf grass 409900 Jan. Feb. Mar. Apr. May. Jun. Jul. Aug. Sep. Oct. Nov. Dec. Sub Total PASSIVE FIELDS Turfgrass 317988 Jan. Feb. Mar. Apr. May. Jun. Jul. Aug. Sep. Oct. Nov. Dec. Application Rate 2.02 2.43 4.21 4.40 5.60 5.15 6.20 5.83 4.12 2.97 2.31 1.83 47.07 1.97 2.38 4.15 4.40 5.60 5.15 6.20 5.83 4.12 2.91 2.26 1.79 Monthly Req. (Gallons) 514978 621406 1076537 1124021 1430135 1316337 1584224 1488508 1051596 759496 590097 468162 12025496 390784 471365 821667 871983 1109456 1021176 1228994 1154740 815797 576112 448265 355258 Peak Flow (0PM) 55 66 115 120 153 141 169 159 112 81 63 50 42 50 88 93 119 109 131 123 87 62 48 38 Sub Total 46.75 9265597 Area Description Irrigated Area Month (Square Foot) PLANTING AREAS Ornamental/Deeert Planting 184259 Jan. Feb. Mar. Apr. May. Jun. Jul. Aug. Sep. Oct. Nov. Dec. Application Rate 0.69 0.83 1.45 1.54 1.96 1.80 2.17 2.04 1.44 1.02 0.79 0.63 Monthly Req. (Gallon*) 79254 95597 166641 176845 225007 207103 249250 234191 165450 116840 90912 72049 Peak Flow (0PM) 8 10 18 19 24 22 27 25 18 12 10 8 Sub Total 16.36 1879139 ALTERNATIVE "B" TOTALS Combined Grace 6 Plant Mixee 912146 Jan. Feb. Mar. Apr. May. Jun. Jul. Aug. Sep. Oct. Nov. Dec. 985016 1188367 2064845 2172849 2764598 2544616 3062468 2877439 2032843 1452448 1129274 895469 105 127 221 232 296 272 327 308 217 155 121 96 Total (Sq. Ft. / Gal.) Total (Acrea / Ac. Ft.) 912146 20.94 23170232 71.1 o Area Description Irrigated Area Month (Square Foot) ALTERNATIVE "C" PLAYING FIELDS Turfgraae 503989 Jan. Feb. Mar. Apr. May. Jun. Jul. Aug. Sep. Oct. Nov. Dec. Sub Total PASSIVE FIELDS Turfgraaa 301000 Jan. Feb. Mar. Apr. May. Jun. Jul. Aug. Sep. Oct. Nov. Dec. Application Rate 2.02 2.43 4.21 4.40 5.60 5.15 6.20 5.83 4.12 2.97 2.31 1.83 47.07 1.97 2.38 4.15 4.40 5.60 5.15 6.20 5.83 4.12 2.91 2.26 1.79 Monthly Req. (Gallon*) 633188 764045 1323649 1382033 1758413 1618493 1947871 1830184 1292982 933833 725549 575625 14785865 369906 446182 777770 825397 1050184 966620 1163335 1093049 772213 545334 424317 336278 Peak Flow (0PM) 68 82 142 148 188 173 208 196 138 100 78 62 40 48 83 88 112 103 124 117 83 58 45 36 Sub Total 46.75 8770585 o f Ar«a Description Irrigated Area (Square Foot) PLANTING AREAS Ornamental /Desert Planting 163350 Month Jan. Fab. Mar. Apr. May. Jun. Jul. Aug. Sep. Oct. Nov. Dec. Application Rate 0.69 0.83 1.45 1.54 1.96 1.80 2.17 2.04 1.44 1.02 0.79 0.63 Monthly Req. (Qalloni) 70261 84749 147731 156778 199474 183602 220966 207616 146676 103582 80596 63873 Peak Flow (0PM) 8 9 16 17 21 20 24 22 16 11 9 7 Sub Total 16.36 1665904 AIiTBRKATIVB "C" XOXJtLS Combined Graaa 6 Plant Mixea 968339 Jan. Feb. Mar. Apr. May. Jun. Jul. Aug. Sep. Oct. Nov. Dec. 1073355 1294976 2249150 2364208 3008071 2768715 3332173 3130849 2211871 1582748 1230462 975777 115 138 240 253 322 296 356 335 236 169 132 104 Total (Sq. Ft. / Gal.) Total (Acre* / Ac. Ft.) 968339 22.23 25222354 77.4 ALTA MIRA PARK PRELIMINARY IRRIGATION CONSTRUCTION ESTIMATE March 24, 1992 ALTERNATIVE "A" (21.21 ACRES) Irrigation @ Turf Small areas - pop-up sprays (2.93 AC) $ 89,000 Medium areas - pop-up sprays (2.93 AC) $ 51,000 Large areas - rotors (11.6 AC) $101,000 Turf Sub-Total $241,000 Irrigation <§> Planting Beds Small areas - drip (1.0 AC) $ 43,500 Slope areas - drip (1.0 AC) $ 26,000 Large areas - drip (1.75 AC) $ 46,000 Planting Sub-Total $ 115,500 Booster Pump Allowance $ 30,000 Irrigation Sub-Total $386,500 Contingency (15%) $ 58,000 Alternative 'A' Total $444,500 ALTERNATIVE "B" (20.94 ACRES) Irrigation @ Turf Small areas - pop-up sprays (2.81 AC) $ 85,000 Medium areas - pop-up sprays (2.81 AC) $ 49,000 Large areas - rotors (11.1 AC) $ 97,000 Turf Sub-Total $231,000 Irrigation @ Planting Beds Small areas - drip (1.0 AC) $ 43,500 Slope areas - drip (1.0 AC) $ 26,000 Large areas - drip (2.23 AC) $ 55,000 Planting Sub-Total $124,500 Booster Pump Allowance $ 30,000 Irrigation Sub-Total $385,500 Contingency (15%) $58,000 Alternative "B" Total $443,500 ALTERNATIVE "C" (27.23 ACRES) Irrigation @ Turf Small areas - pop-up sprays (3.0 AC) $ 91,500 Medium areas - pop-up sprays (3.0 AC) $ 52,000 Large areas - rotors (12.48 AC) $107,000 Turf Sub-Total $250.500 Irrigation @ Planting Beds Small areas - drip (.94 AC) $ 40,500 Slope areas - drip (.94 AC) $ 24,500 Large areas - drip (1.87 AC) * 49,000 Planting Sub-Total $ 114,000 Booster Pump Allowance $ 30,000 Irrigation Sub-Total $394,500 Contingency (15%) $59,000 Alternative "C- Total $453,500