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HomeMy WebLinkAboutHARMONY TECHNOLOGY PARK THIRD - Filed GR-GEOTECHNICAL REPORT/SOILS REPORT -PRELIMINARY GEOTECHNICAL EXPLORATION REPORT 5305 ZIEGLER ROAD—NORTH/LOT 1 FORT COLLINS, COLORADO EEC PROJECT NO. 1122052A Prepared for: Architecture West, LLC 4710 South College Avenue Fort Collins, Colorado 80525 Attn: Mr. Stephen Steinbicker(Steve(a,architecturewestllc.com) Prepared by: Earth Engineering Consultants, Inc. 4396 Greenfield Drive Windsor, Colorado 80550 EEC July 11, 2012 4:* EARTH ENGINEERING CONSULTANTS, INC. Architecture West, LLC 4710 South College Avenue Fort Collins, Colorado 80525 Attn: Mr. Stephen Steinbicker(Steve(c&architecturewestllc.com) Re: Preliminary Geotechnical Exploration Report 5305 Ziegler Road—North/Lot 1 Fort Collins, Colorado EEC Project No. 1122052A Mr. Steinbicker: Enclosed, herewith, are the results of the preliminary geotechnical subsurface exploration completed by Earth Engineering Consultants, Inc. (EEC) personnel for the proposed development of Lot 1 north of County Fair Lane at 5305 Ziegler Road in Fort Collins, Colorado. We understand the property at 5305 Ziegler Road consists of an approximate 3.75 acre parcel split into a north parcel (lot 1) located north of County Fair Lane and a south parcel (Lot 2) located south of that roadway. County Fair Lane has yet to be constructed across this property. We understand the north parcel is expected to be developed with two (2) office/retail buildings. However, these buildings could also be constructed as multi-family similar to the south parcel. The structures may have full basements. Foundation loads are anticipated to be light. Small grade changes are expected to develop site grading. Drive and parking will be developed off of County Fair Lane. The subsurface soils encountered at the four(4) test boring locations on the north parcel included near surface sandy lean clays extending to a depth of approximately 20 feet below present site grade in boring B-3 and to the bottom of the other borings at depths of approximately 15 to 20 feet. The lean clay in boring B-3 was underlain by highly weathered sandstone/siltstone/claystone bedrock. The near surface cohesive soils generally showed moderate potential to swell with increased moisture content and load. Based on results of the field borings and laboratory testing, we anticipate overexcavation and moisture conditioning of dry, hard cohesive soils will be required to reduce potential for swelling of the subgrade materials and resultant movement of foundations or floor slabs. We expect foundations for 4396 GREENFIELD DRIVE WINDSOR, COLORADO 80550 970) 545-3908 FAX (970) 663-0282 www.earth•engineering.com Earth Engineering Consultants,Inc. EEC Project No. 1122052A July 11,2012 Page 2 the buildings could consist of conventional footings supported on a zone of reconditioned site soils, footings supported on newly placed structural fill or on drilled pier foundations. We expect the floor slabs could be supported on the site sandy lean clay subgrade materials reconditioned/processed to a suitable depth to reduce swell potential. Those materials could also be used for support of pavements with expected stabilization of the subgrade surface through the addition of Class"C" fly ash. Free groundwater was observed at depths on the order of 14 to 17 feet below present site grades. We understand basement construction would extend to depths of approximately 10 feet. Preliminary geotechnical recommendations concerning design and construction of the proposed buildings and general site development are provided in the attached report. If you have any questions concerning this report, or if we can be of further service to you in any other way,please do not hesitate to contact us. Very truly yours, Earth Engineering Consultants, Inc. Lester L. Litton, P.E. Principal Engineer Reviewed by: David A. Richer,P.E. Senior Project Engineer LLL/DAR/dla PRELIMINARY GEOTECHNICAL EXPLORATION REPORT 5305 ZIEGLER ROAD—NORTH/LOT 1 FORT COLLINS, COLORADO EEC PROJECT NO. 1122052A July 11, 2012 INTRODUCTION The geotechnical subsurface exploration for the proposed north parcel — Lot 1 at 5305 Ziegler Road in Fort Collins, Colorado, has been completed. Four(4) soil borings were completed at predetermined locations on the Lot 1 parcel to develop information on existing subsurface conditions. The borings were extended to depths of approximately 15 to 30 feet below present site surface grade. Individual boring logs and a diagram indicating the approximate boring locations are included with this report. The development parcel at 5305 Ziegler Road includes approximately 3.75 acres divided as a north parcel(Lot 1) located north of County Fair Lane and a south parcel(Lot 2)located to the south of that roadway. Two(2)office/retail buildings are expected to be developed on the north parcel. Those structures are expected to have light foundation loads, less than 3 kips per lineal foot for continuous wall loads and less than 100 kips for column loads. As an alternative, the north buildings may be multi-family units similar to the south parcel buildings. The multi-family units may have full basements. Small grade changes are expected to develop the final site grades in the vicinity of the proposed buildings. Paved drive and parking areas will be constructed as a part of the proposed development. The purpose of this report is to describe the subsurface conditions encountered in the borings, analyze and evaluate the test data and provide preliminary geotechnical recommendations concerning design and construction of foundations and support of floor slabs and pavements EXPLORATION AND TESTING PROCEDURES The proposed boring locations were selected in collaboration with Architecture West and located in the field by Earth Engineering Consultants, Inc. (EEC) personnel by pacing and estimating angles from identifiable site references. The approximate locations of the borings are indicated on the attached boring location diagram. The location of the borings should be Earth Engineering Consultants,Inc. EEC Project No. 1122052A July 11,2012 Page 2 considered accurate only to the degree implied by the methods used to make the field measurements. The test borings were completed using a truck mounted,CME-45 drill rig equipped with a hydraulic head employed in drilling and sampling operations. The boreholes were advanced using 4-inch nominal diameter continuous flight augers. Samples of the subsurface materials encountered were obtained using split-barrel and California barrel sampling procedures in general accordance with ASTM Specifications D1586 and D3550, respectively. In the split-barrel and California barrel sampling procedures,standard sampling spoons are driven into the ground by means of a 140-pound hammer falling a distance of 30 inches. The number of blows required to advance the split barrel and California barrel samplers is recorded and is used to estimate the in-situ relative density of cohesionless soils and, to a lesser degree of accuracy, the consistency of cohesive soils. In the California barrel sampling procedure,relatively undisturbed samples are obtained in removable brass liners. All samples obtained in the field were sealed and returned to the laboratory for further examination, classification, and testing. Laboratory moisture content tests were completed on each of the recovered samples. In addition, the unconfined strength of appropriate samples was estimated using a calibrated hand penetrometer. Atterberg limits and washed sieve analysis tests were completed on selected samples to evaluate the quantity and plasticity of the fines in the subgrade. Swell/consolidation tests were completed on selected samples to evaluate the potential for the subgrade materials to change volume with variation in moisture content and load. Soluble sulfate tests were performed on selected samples to evaluate the potential for sulfate attack on site cast concrete. Results of the outlined tests are indicated on the attached boring logs and summary sheets. As a part of the testing program,all samples were examined in the laboratory by an engineer and classified in accordance with the attached General Notes and the Unified Soil Classification System, based on the soil's texture and plasticity of the soil. The estimated group symbol for the Unified Soil Classification System is indicated on the boring logs and a brief description of that Classification System is included with this report. Classification of Earth Engineering Consultants,Inc. EEC Project No. 1122052A July 11,2012 Page 3 the bedrock was based on visual and tactual observation of disturbed samples and auger cuttings. Coring and/or petrographic analysis may reveal other rock types. SITE AND SUBSURFACE CONDITIONS The proposed development is located on the west side of Ziegler Road,north of Kechter,in Fort Collins,Colorado. The development property was formerly part of the Ruff Feedlot and still contains several outbuildings. Most recently,the property has been used for truck and miscellaneous storage. We understand the site structures will be razed to accommodate the planned development. Site drainage is generally to the south toward McClelland Creek which borders the south parcel to the south. An EEC field engineer was on site during drilling operations to evaluate the subsurface conditions encountered and to direct the drilling activities. Field logs prepared by EEC site personnel were based on visual and tactual observation of disturbed samples and auger cuttings. The final boring logs included with this report may contain modifications to the field logs based on results of laboratory testing and evaluation. Based on results of the field borings and laboratory evaluation, subsurface conditions can be generalized as follows. Surface materials on the north parcel generally included sparse vegetation and/or topsoil. The topsoil/vegetation was underlain by brown lean clay with varying amounts of sand. The cohesive soils were generally very stiff to hard and were generally dry to very dry. The low moisture content clay soils showed moderate swell potential in laboratory testing. The lean clay soils extended to the bottom of borings B-1,B-2 and B-4 at depths on the order of 15 to 20 feet below present ground surface. The cohesive soils extended to a depth of approximately 20 feet in boring B-3 and were underlain by highly weathered to weathered siltstone/sandstone/claystone bedrock. The bedrock formation generally became less weathered with depth and extended to the bottom of boring B-3 at a depth of approximately 30 feet below existing site grades. The stratification boundaries indicated on the boring logs represent the approximate locations of changes in soil and bedrock types. In-situ, the transition of materials may be gradual and indistinct. Earth Engineering Consultants,Inc. EEC Project No. 1122052A July 11,2012 Page 4 GROUNDWATER CONDITIONS Observations were made while drilling and after completion of the borings to detect the presence and depth to hydrostatic groundwater. In addition, field slotted PVC piezometers were installed at four (4) boring locations on the overall site to allow for short term monitoring of groundwater levels. At the time of our field exploration, groundwater was observed at depths on the order of 16 feet below ground surface. Measurements in the field piezometers approximately 2 weeks after the initial drilling indicate groundwater levels ranging from approximately 14 to 18 feet below existing ground surface. Depths to groundwater are indicated in the upper hand corners of the boring logs. Fluctuations in groundwater levels can occur over time depending on variations in hydrologic conditions and other conditions not apparent at the time of this report. Monitoring of groundwater levels in cased boring which are sealed from the influence of surface water will be required to more accurately evaluate the depth and fluctuations in groundwater levels on the site. Zones of perched and/or trapped groundwater may occur at times in the subsurface soils overlying bedrock, on top of the bedrock surface or within permeable fractures within the bedrock. The location and amount of perched/trapped water is depended on several factors including hydrologic conditions,type of site development,irrigation demands on or adjacent to the site and fluctuations in water levels in McClelland Creek on the southern boundary of the property as well as seasonal weather conditions. Observations submitted with this report represent groundwater conditions at the time of the field exploration and may or may not be indicative of other times or other locations. ANALYSIS AND RECOMMENDATIONS SwelUConsolidation Test Results The swell/consolidation test is performed to evaluate swell or collapse potential of soils or bedrock for determining foundation, floor slab and pavement design criteria. In this test, Earth Engineering Consultants,Inc. EEC Project No. 1122052A July 11,2012 Page 5 relatively undisturbed samples obtained from the California barrel sampler or thin-walled tubes are placed in a laboratory apparatus and inundated with water under a predetermined load. The swell index is the resulting amount of swell or collapse after the inundation period,expressed as a percent of the sample's initial thickness. After the inundation period, additional incremental loads are applied to evaluate the swell pressure and consolidation of the tested sample. For the north parcel of the development, we conducted five(5) swell/consolidation tests at varying depths throughout the north portion of the site. The swell index values for the soils samples revealed moderate swell characteristics ranging from approximately 2.4 to 4.5% swell. A swell of approximately 2.7% was measured in the underlying bedrock. The Colorado Association of Geotechnical Engineers (CAGE) uses the following information in Table I, to provide uniformity in terminology between geotechnical engineers to provide a relative correlation of slab performance risk to measured swell. "The representative percent swell values are not necessarily measured values;rather,they are a judgment of the swell of the soil and/or bedrock profile likely to influence slab performance." Geotechnical engineers use this information to also evaluate the swell potential risks for foundation performance based on the risk categories. TABLE I:Recommended Representative Swell Potential Descriptions and Corresponding Slab Performance Risk Categories Slab Performance Risk Category Representative Percent Swell Representative Percent Swell 500 psf Surcharge) 1000 psf Surcharge) Low 0to<3 0<2 Moderate 3 to<5 2 to<4 High 5to<8 4to<6 Very High 8 6 Based on the outlined criteria, the soil samples for this site showed moderate swell potential. Site Preparation The near subgrade materials showed approximately 21/2 to 41/2% swell at a dead load of 500 psf. The near surface cohesive soils were relatively dry and hard resulting in the higher Earth Engineering Consultants,Inc. EEC Project No. 1122052A July 11,2012 Page 6 observed swell. Removal and replacement of the excessively dry and hard subgrade soils will be required beneath any foundations, floor slabs, pavements and exterior flatwork. All existing vegetation and/or topsoil should be removed from any site improvement or fill area. In addition, any excessively dry and hard cohesive subgrade soils should be removed laterally to at least 5 feet outside the perimeter of site building or pavements and to a depth consistent with developing acceptable risk of post-construction movement. We expect minimum overexcavation depths of 3 to 4 feet in pavement and flatwork areas where greater movements would be tolerable and depths of 6 feet or greater in building areas. Post- construction slab-on-grade foundations could be constructed in lesser depth of overexcavation. We understand existing site structures will be razed prior to constructing the planned site improvements. All structure elements(footings, floor slabs, sidewalks,patios, etc.)should be removed from the site along with any existing fill or backfill soils associated with the existing site structures. After stripping and completing all cuts and prior to placement of any fill, foundations, floor slabs or pavements, the exposed subgrade should be scarified to a minimum depth of 9 inches, adjusted in moisture content and compacted to at least 95% of the materials' maximum dry density as determined in accordance with ASTM Specification D-698, the standard Proctor procedure. The moisture content of the scarified soils should be adjusted to be within the range of-1 to +3%of standard Proctor optimum moisture. Fill materials required to develop the building and pavement subgrades should consist of approved,low volume change materials which are free from organic matter and debris. The site sandy lean clay/clayey sand soils could be used as fill in these areas. Imported granular structural fill may be considered to reduce the post-construction movement potential. Site fill materials should be relatively uniform across individual building and/or pavement areas. Sandy lean clay/clayey sand fill materials should be placed in loose lifts not to exceed 9 inches thick,adjusted in moisture content as outlined for the scarified soils and compacted to at least 95% of the materials' standard Proctor maximum dry density. Earth Engineering Consultants,Inc. EEC Project No. 1122052A July 11,2012 Page 7 After placement of fill materials, care should be taken to prevent disturbing of prepared subgrades. Care should also be taken to prevent excessive drying or densification of the subgrade materials and wetting of those materials. Construction traffic routes on the site can result in excessive densification of the subgrade soils. Foundations Footing foundations for the buildings would be supported on newly placed and compacted fill consisting of processed site sandy lean clays or imported granular structural fill. For design of footing foundations bearing on acceptable newly placed and compacted fill as outlined in the Site Preparation portion of this report,we recommend using a net allowable total load soil bearing pressure not to exceed 1,500 psf. The net bearing pressure refers to the pressure at foundation bearing level in excess of the minimum surrounding overburden pressure. Exterior foundations and foundations in unheated areas should be located a minimum of 30 inches below adjacent exterior grade to provide frost protection. We recommend formed continuous footings have a minimum width of 12 inches and isolated column foundations have a minimum width of 24 inches. A minimum dead load pressure would not be required in the low swell potential placed fill soils. No unusual problems are anticipated in completing excavation required for construction of the footing foundations. Care should be taken to see that the footing foundations are supported on suitable strength moisture conditioned fill soils and that the subgrade/bearing soils are not overly dry and dense or wet and softened at the time of the footing concrete placement. Soils which are loosened or disturbed by the construction activities or materials becoming dry and desiccated or wet and softened will require removal and replacement or reworking in-place prior to placement of foundation concrete. Floor Slab Subgrades Floor slab subgrades should be prepared as outlined in the Site Preparation section of this report. After preparation of subgrades, care should be taken to prevent disturbing the in- Earth Engineering Consultants,Inc. EEC Project No. 1122052A July 11,2012 Page 8 place subgrade materials. Subgrade materials which are loosened or disturbed by the construction activities or materials which are dry and dense or wet and softened should be removed and replaced prior to placement of overlying floor slab concrete. Care will be needed to prevent creating significant moisture variations in the subgrade soils subsequent to construction. The cohesive soils can show volume change characteristics with excessive drying or wetting. Excessive drying of the subgrade soils through tree and shrub root systems can cause shrinkage of subgrade soils and differential movement of foundations, floor slabs and flatwork. Positive drainage should be developed away from the building with a minimum slope of 1- inch per foot for the first 10 feet away from the structure within landscape areas. Flatter slopes can be developed in flatwork areas provided positive drainage is maintained away from the structure. Basement Area Construction Free groundwater was observed at depths on the order of 17 feet below present site grades at the time of our field exploration. Concerning lateral loads on the basement walls,we suggest those walls be designed using at- rest soil bearing pressure in appropriate cohesive and cohesionless soils zones. Estimated friction angles and associated coefficients oflateral pressures are provided below in Table 1. Equivalent fluid pressure is calculated by multiplying appropriate coefficient by the appropriate soil unit weight. Below the water table, additional pressure extended by the hydrostatic loads on the walls should be added to the estimated soil pressure. Earth Engineering Consultants,Inc. EEC Project No. 1122052A July 11,2012 Page 9 Table I—Lateral Earth Pressure Design Values Soil Type Low Plasticity Cohesive Medium Dense Granular Wet Unit Weight 115 135 Saturated Unit Weight 135 140 Friction Angle(0)—(assumed) 25° 35° Active Pressure Coefficient 0.40 0.27 At-rest Pressure Coefficient 0.58 0.43 Passive Pressure Coefficient 2.46 3.70 The outlined lateral earth pressure coefficients and soil unit weights do not include a factor of safety. An appropriate factor safety should be used for design of the lateral pressures of the below grade walls. Surcharge loads placed in the backfill adjacent to the walls or at subgrade adjacent to the walls, such as first floor level footings or floor slabs or adjacent drive and parking areas, could result in additional loads on the below grade walls. Additional recommendations concerning construction of the below grade area below the water table can be provided upon request. Seismic The observed subsurface conditions at the site consist of approximately 17 feet of stiff/moderately dense soils overlying moderately hard weathered bedrock. Those subsurface conditions indicate a site Classification of D using the 2009 International Building Code System. Pavements Subgrades in the pavement areas should be generally prepared as outlined for Site Preparation. However,site sandy lean clay soils and clayey sand soils may show instability on strength loss when wetted. The instability will be visible through pumping and/or rutting Earth Engineering Consultants,Inc. EEC Project No. 1122052A July 11,2012 Page 10 of the subgrades in the pavement areas prior to placement of the overlying pavement structure. To allow for placement of a pavement section on a stable subgrade, we recommend consideration be given to stabilization of the pavement subgrade through the addition of Class C fly ash. We recommend blending 13%Class C fly ash by dry weights for the top 12 inches of the subgrade beneath the pavement section to provide stable subgrade support. The blended materials should be adjusted in moisture content to ±2% of standard Proctor optimum moisture and compacted to at least 95% of the materials standard Proctor maximum dry density. Compacting soils slightly dry of optimum moisture for maximum dry density will result in higher compressive strengths. In addition to developing a stable subgrade for the pavement construction, stabilization of subgrade can be utilized to reduce the required asphalt and/or aggregate base for the pavement section. We recommend the pavement section consisting of 31/2 inches of hot bituminous pavement (HBP) overlying 4 inches of aggregate base course (ABC) for light traffic/light load areas with a section including 4 inches of HBP overlying 6 inches of ABC for more heavily traffic/loaded drive and entry areas. The HBP should be grading S or SX 75 and the ABC should be Class 5 or Class 6 aggregate base. In areas of truck turning and/or trash truck routes,we recommend the use of Portland cement concrete surface. A minimum of 6 inches of Portland cement concrete supported on a stabilized base should be constructed in these areas. Portland cement concrete for use in the pavement areas should be an exterior pavement mix with a 28-day compressive strength of at least 4,000 psi and should be air entrained. Sulfate Considerations The water soluble sulfate (SO4) testing of the on-site overburden subsoils indicated sulfate contents generally less than 1 pps or contents less than 150 ppm,sulfate(SO4)in water,or less than 0.1%water soluble sulfate(SO4)in soils,percent by weight,are considered negligible risk of sulfate attack on Portland cement concrete. Less than 150 ppm results would typically indicate that ASTM Type I Portland cement is suitable for all concrete on and below grade. Earth Engineering Consultants,Inc. EEC Project No. 1122052A July 11,2012 Page 11 Therefore, based on the results as presented herein it appears Type I or Type I/II Portland cement could be used for site cast-in-place concrete. Foundation concrete should be designed in accordance with the provisions of the ACI Design Manual, Section 318,Chapter 4. GENERAL COMMENTS The analysis and recommendations presented in this report are based upon the data obtained from the soil borings performed at the indicated locations and from any other information discussed in this report. This report does not reflect any variations, which may occur between borings or across the site. The nature and extent of such variations may not become evident until construction. If variations appear evident,it will be necessary to re-evaluate the recommendations of this report. It is recommended that the geotechnical engineer be retained to review the plans and specifications so comments can be made regarding the interpretation and implementation of our geotechnical recommendations in the design and specifications. It is further recommended that the geotechnical engineer be retained for testing and observations during earthwork and foundation construction phases to help determine that the design requirements are fulfilled. This report has been prepared for the exclusive use of Architecture West, LLC for specific application to the project discussed and has been prepared in accordance with generally accepted geotechnical engineering practices. No warranty, express or implied, is made. In the event that any changes in the nature,design,or location of the project as outlined in this report are planned, the conclusions and recommendations contained in this report shall not be considered valid unless the changes are reviewed and the conclusions of this report are modified or verified in writing by the geotechnical engineer. DRILLING AND EXPLORATION DRILLING&SAMPLING SYMBOLS: SS: Split Spoon- 13/8" I.D.,2"O.D.,unless otherwise noted PS: Piston Sample ST: Thin-Walled Tube-2" O.D.,unless otherwise noted WS: Wash Sample R: Ring Barrel Sampler-2.42" I.D.,3"O.D.unless otherwise noted PA: Power Auger FT: Fish Tail Bit HA: Hand Auger RB: Rock Bit DB: Diamond Bit=4",N,B BS: Bulk Sample AS: Auger Sample PM: Pressure Meter HS: Hollow Stem Auger WB: Wash Bore Standard"N"Penetration: Blows per foot of a 140 pound hammer falling 30 inches on a 2-inch O.D.split spoon,except where noted. WATER LEVEL MEASUREMENT SYMBOLS: WL : Water Level WS : While Sampling WCI: Wet Cave in WD: While Drilling DCI: Dry Cave in BCR: Before Casing Removal AB : After Boring ACR: After Casting Removal Water levels indicated on the boring logs are the levels measured in the borings at the time indicated. In pervious soils,the indicated levels may reflect the location of ground water. In low permeability soils,the accurate determination of ground water levels is not possible with only short term observations. DESCRIPTIVE SOIL CLASSIFICATION DEGREE OF WEATHERING: Soil Classification is based on the Unified Soil Classification Slight Slight decomposition of parent material on system and the ASTM Designations D-2488. Coarse Grained joints. May be color change. Soils have move than 50%of their dry weight retained on a#200 Moderate Some decomposition and color change sieve;they are described as: boulders,cobbles,gravel or sand.throughout. Fine Grained Soils have less than 50% of their dry weight High Rock highly decomposed,may be extremely retained on a#200 sieve;they are described as: clays,if they broken. are plastic, and silts if they are slightly plastic or non-plastic. HARDNESS AND DEGREE OF CEMENTATION: Major constituents may be added as modifiers and minor Limestone and Dolomite: constituents may be added according to the relative proportions Hard Difficult to scratch with knife. based on grain size. In addition to gradation, coarse grained Moderately Can be scratched easily with knife. soils are defined on the basis of their relative in-place density and fine grained soils on the basis of their consistency. Hard Cannot be scratched with fingernail. Example: Lean clay with sand, trace gravel, stiff(CL); silty Soft Can be scratched with fingernail. sand,trace gravel,medium dense(SM). Shale,Siltstone and Claystone: CONSISTENCY OF FINE-GRAINED SOILS Hard Can be scratched easily with knife,cannot be scratched with fingernail. Unconfined Compressive Moderately Can be scratched with fingernail. Strength,Qu,psf Consistency Hard Soft Can be easily dented but not molded with 500 Very Soft fingers. 500- 1,000 Soft Sandstone and Conglomerate: 1,001 - 2,000 Medium Well Capable of scratching a knife blade. 2,001 - 4,000 Stiff Cemented 4,001 - 8,000 Very Stiff Cemented Can be scratched with knife. 8,001 - 16,000 Very Hard Poorly Can be broken apart easily with fingers. RELATIVE DENSITY OF COARSE-GRAINED SOILS: Cemented N-Blows/ft Relative Density 0-3 Very Loose 4-9 Loose 10-29 Medium Dense 30-49 Dense 50-80 Very Dense 80+ Extremely Dense PHYSICAL PROPERTIES OF BEDROCK TIN. r. SOIL CLASSJ FJ CATI©N SYSTEM 1 Soil Classification i Group Group Name Criteria for Assigning Croup Symbols and Group names Using Laboratory Tests Symbol Coarse—Grained Gravels more than Clean Gravels Less Soils more than 50% of coarse than 5% fines Cu>4 and <tic<3E GW Well—graded gravel` 50% retained on fraction retained No. 200 sieve on No. 4 sieve Cu<4 and/or 1>Cc>3E GP Poorly—graded gravel' Grovels with Fines Fines classify as ML or MH GM Silty gravel, G,H more than 12% fines Fines classify as CL or CH GC Clayey Gravel r." Sands 50% or Clean Sands Less Cu»5 and 1<C.cS3` SW Well—graded sand' more coarse than 5% fines fraction passes Cu<6 and/or 7>Cc>3` SP Poorly—graded sand' No. 4 sieve Sands with Fines Fines classify as ML or MH SM Silty sand`'more than 12% fines Fines classify es CL or Chi SC Clayey sandr4n' Fine—Grained Silts and Clays inorganic PI>7 and plots on or above "A-Line CL Leon cloyl" Soils 509. or Liquid Limit less more posses the than 50 PI<4 or plots below "A"Line ML Silt' No. 200 sieve organic Liquid Limit — oven dried Organic clay L 0.75 OL Liquid Limit — not dried Organic silt e'`'Y" Silts and Clays inorganic PI plots on or above -Aline CH Fct clay"Liquid Limit 50 or more PI plots below "Aline MH Elastic Siitut" organic Liquid limit — oven dried Organic clay' 0.75 OH Liquid Limit — not dried Organic silt°°0 Highly organic soils Primarily organic matter, dark in color, and organic odor PT Peat Based on the material parsing the 3-in. (75- c 0 D,5 sit soil contoins 15 to 297,plus No. 20C, add mm) sieve Cu= DDno/01 Cc=x with sand" or 'with grovel, whichever is It field sample contained cobbles or boulders, predominant- or bath, add 'with cobbles or boulders. or both" uIf sot contains 2 30- plus No. 200 to group name. 9f sot contains 2155 sand. add-with sand"too predominantly sand, odd 'sandy to groupGrovelswith5to12Xfinesrequireddual group name, nee symbol... of foes classify as CL-Mt, use dual symbol If soO contains 2 3UX plus Na. 200GW-CM well graded grovel with silt GC-CM, or SC-SM. predominantly grovel, add "gravely to group CW-GC well-graded gravel with cloyif foes ore organic, add-with organic fines-to m e. GP-CM poorly-graded grovel with slit group name P154 and plots on cr cbove 'A" fine.SP-GC poorly-graded grovel with clay PI54 or plots below -A' line.II sot contains >15Sgrovel, add"with gavel'Sands with 5 to 12% foes require dud to group name. Pi plots an or above -A line. symbols: lit Atterberg limits plots shaded area, sot is a Pt plots below "A" fine.SW-SM well--graded sand with silt CL-WL, nifty clay,5W-SC well-graded sand with clay 5P-SM poorly graded sand with silt SP-SC poorly graded sand with clay 60 For OcaiBcotbn of Me-grained son rs and fee-soyined fraction of coarse wooled sods 90 Equation off-A'-tiv IHuruontolor94-4 to LL-29-0, c/ C' Cm PI-0.73(L1-20) v'4'iiEquationofU'-tin. J// 1.0\>‘ .,F,w 4a_ Verlleof of LL"15 to P1.7, p X then P1=0.9(LL-5) O e' Gz r 30- 0 U F- OvIn20- MH OH1A /is- i s i/-M L aR 0 L 00/Ma Mill102030405050705090100 t10 LIQUID OMIT (LL) I _ _ _ _ _T I J It 1 1 1 I o t ,_, T.I I \\/ f" 1 1 North Parcel 1 1 FOSSIL110 \ Lot 1 v 1\ 1 It B-1' 1122os2A s 1 , ^ t' `.,' I _ r- R I D G 1 11,h.I H I G H t L, SCHOOL IIIi J s i } ice \\ I I OFFICE I' I I j 1 i; Nap mc l I v I_ B y ", 1 I I Q MINK 1 `\ I SABER CAT B-Z __ l r 11 f-- DRIVE 1 I I % _ -- 1 ,, I f to 1Ei 0 t ,' 1 i!' i B-6 11 1 I I B-5 I 1 1 Q i 1 % 1 1 i 11 6-PLEX b-1'.!-X,, ' I 1 1 Q I I t 1 7- / ; I 11 1 I 14. ' 1 t / 1 I tf I\1 w 11 Y South Parcel 1 \ Y I Lot 2 , B-7 r11 4 1122052 5 7 iI r I i t 1 r I f 1 1 ; 1 1 N o r ! i f t%W / I j/ 11111 1ll t 0 I :II1 v/ I \ t 1 lI b-r61(b-FLEX s• 1I I I1 1 ILI r1 I — 11Ir%;;% f// 1;y` rl NI Jirr lI I Y1, ir rr ri i7 1 I I t 1 1 ri 1//J i, 1 1 `1 III 11 i i' g,g— _ , 1 - B-9 ; III Ill i i,11 riff fie 11 II I I liax' B-1I0 j 6 IJ 1 I l\ \\ ft Legend ti,,,_ I i to 1 1 1 / Iis Approximate Boring 1 Locations r= • , 1 a Site Photos j`` `"= _ _ _ i I /1 photos taken in approximate ` me G L e L L A N I I/ location,in direction ofarrow/ n•\a D G R E k I 1 Boring Location Diagram15305ZieglerRoad Fort Collins, Colorado North EEC Project Number: 1122052 Date:June 2012 Not to Scab EARTH ENGINEERING CONSULTANTS, INC- t i.;-.ii...i7 MIS II I- 7„,..se.? ,t___j _.. _-a", • ", " ..••• Ir• Ik 1 _. dr..._. _ r- - I r ' :Att-if e, 4 * -.........,"..Am;• - I let t'.. 17.•• i- .,..„.........„„... 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Y Y 1 Heft d i. 1 T Jr,,,,, r . i 4 gtet.44---4E.,0" i41., . , 1211 0 0 e 61 t:.,:,....), " ,,,,: o. •--.4r- HARVEST MIXED USE FORT COLLINS,COLORADO E1111.EEC PROJECT No.1122052 v_ JUNE 2012 5305 ZIEGLER ROAD FORT COLLINS,COLORADO PROJECT NO: 1122052 DATE: JUNE 2012 LOG OF BORING B-1 RIG TYPE: CME45 SHEET 1 OF 1 WATER DEPTH FOREMAN: DG START DATE 6/19/2012 WHILE DRILLING None AUGER TYPE: 4"CFA FINISH DATE 6/19/2012 AFTER DRILLING NIA SPT HAMMER: MANUAL SURFACE ELEV NIA 24 HOUR NIA SOIL DESCRIPTION D N pU MC DO A-LIMITS I -200 SWELL TYPE (FEET) (BLOWS/FT) IPSF)I°'o) (PCF) LL PI (/) PRESSURE %5 500 PSF TOPSOIL&VEGETATION 1 SANDY LEAN CLAY(CL) brown 2 stiff to very stiff with calcareous deposits 1 CS 3 14 9000+ 11.4 110.6 49 33 69.2 2600 psf 3.2% 4 SS -5 15 9000+ 8.4 6 7 8 9 ICS 10 25 9000+ 11.3 120.9 1-1 12 13 14 SS 15 9 5500 19.4 BOTTOM OF BORING DEPTH 15.5' 1E 17 18 19 20 21 22 23 24 25 Earth Engineering Consultants 5305 ZIEGLER ROAD FORT COLLINS,COLORADO PROJECT NO: 1122052 DATE: JUNE 2012 LOG OF BORING B-2 RIG TYPE: CME45 SHEET 1 OF 1 WATER DEPTH FOREMAN: DG START DATE 6/19/2012 WHILE DRILLING 14.0' AUGER TYPE: 4"CFA FINISH DATE 611 912 01 2 AFTER DRILLING N/A SPT HAMMER: MANUAL SURFACE ELEV NIA 24 HOUR NIA SOIL DESCRIPTION O N OU MC DO A-LIMITS 200 SWELL TYPE (FEET) (BLOWS/FT) (PSF)PCP) LL PI (%) PRESSURE %g 500 PSF TOPSOIL&VEGETATION 1 SANDY LEAN CLAY(CL) brown 2 stiff to very stiff with calcareous deposits 3 4 CS 5 31 9000+ 9.4 121.5 31 15 58.8 4000 psf 2.4 6 7 8 9 SS 10 10 9000+ 11.3 11 12 13 14 gravelly seam CS 15 20 13.0 116.9 BOTTOM OF BORING DEPTH 15.0' 16 17 18 19 20 21 22 23 24 2-5 Earth Engineering Consultants 5305 ZIEGLER ROAD FORT COLLINS,COLORADO PROJECT NO: 1122052 DATE: JUNE 2012 LOG OF BORING B-3(PIEZOMETER) RIG TYPE: CME45 SHEET 1 OF 1 WATER DEPTH FOREMAN: DG START DATE 6119/2012 WHILE DRILLING 17.0' AUGER TYPE: 4"CFA FINISH DATE 6119/2012 7/5/2012 17.7' SPT HAMMER: MANUAL SURFACE ELEV NIA 24 HOUR 17.7' SOIL DESCRIPTION 0 N oU MC DO A-LIMITS I -200 SWELL TVPE (FEET) (BLOWS/FT) (PSF)a) (PCF) LL PI (14) PRESSURE % 500 TOT TOPSOIL&VEGETATION SANDY LEAN CLAY(CL) brown 2 stiff to very stiff with calcareous deposits 4 ICS 5 14 9000+ 11.1 109.0 4400 psf 4.5% 6 7 8 SS 10 21 9000+ 6.8 11 12 13 14 ICS 15 12 9000* 14.4 110.9 16 17 18 19 SS 20 24 11.7 CLAYSTONE I SILTSTONE/SANDSTONE 21 brown/grey/rust highly weathered 22 23 24 ICS 25 50/6" Continued on Sheet 2 of 2 Earth Engineering Consultants 5305 ZIEGLER ROAD FORT COLLINS,COLORADO PROJECT NO: 1122052 DATE: JUNE 2012 LOG OF BORING B-3(PIEZOMETER) RIG TYPE: CME45 SHEET 2 OF 2 WATER DEPTH FOREMAN: DG START DATE 6/1 912 01 2 WHILE DRILLING 17.0' AUGER TYPE: 4"CFA FINISH DATE 6/1912012 7/5/2012 17.7' SPT HAMMER: MANUAL SURFACE ELEV NIA 24 HOUR 17.7' SOIL DESCRIPTION D N QV MC DD A-LIMITS 200 SWELL TYPE (FEET) (BLOWS/FT) (PSI)PCF) LL PI (%) PRESSURE IE 500 PSF Continued from Sheet 1 of 2 26 CLAYSTONE/SILTSTONE I SANDSTONE 2-7 brown/grey/rust highly weathered 28 2-9 CS 30 50/6" 7000 21.3 48 27 93.1 7500 psf 2.7% BOTTOM OF BORING DEPTH 30.0' 31 3-2 3-3 34 3-5 3-6 37 3-8 39 4-0 41 42 4-3 4-4 45 46 47 48 4-9 5-0 Earth Engineering Consultants 5305 ZIEGLER ROAD FORT COLLINS,COLORADO PROJECT NO: 1122052 DATE: JUNE 2012 LOG OF BORING B4 RIG TYPE: CME45 SHEET 1 OF 1 WATER DEPTH FOREMAN: DG START DATE 6/19/2012 WHILE DRILLING 18.0' AUGER TYPE: 4"CFA FINISH DATE 6/19/2012 AFTER DRILLING N/A SPT HAMMER: MANUAL SURFACE ELEV N/A 24 HOUR N/A SOIL DESCRIPTION D N oU MC DO A-LIMITS I -200 SWELL TYPE (FEET) (BLOWS/FT) (PSF)NI (PCF) LL PI (a) PRESSURE %E 500 PSF TOPSOIL&VEGETATION 1 SANDY LEAN CLAY(CL) brown 2 stiff to very stiff 3 4 CS 5 24 9000. 10.4 116.9 5200 psf 4.1% 6 7 9 ICS 10 17 9000+ 7.5 121.4 1-1 12 1-3 1-4 traces of gravel SS 15 10 6500 19.6 16 17 18 sand&gravel seam 19 CS 20 25 11.5 123.7 BOTTOM OF BORING DEPTH 20.0' 21 22 23 24 25 Earth Engineering Consultants SWELL /CONSOLIDATION TEST RESULTS Material Description: Brown Sandy Lean Clay(CL) Sample Location:Boring 1, Sample 1, Depth 2' Liquid Limit: 49 Plasticity Index: 33 Passing#200: 69.2% Beginning Moisture: 11.4% Dry Density: 115.4 pcf Ending Moisture: 18.5% Swell Pressure: 2600 psf Swell @ 500: 3.2% 10.0 8.0 6.0 co 4.0 2.0 " 2 0.0 Water Added2.0 4.0 - 0 coco 0 N o -6.0 U 8.0 10.0 0.01 0'1 1 10 Load(TSF) Project: 5305 Ziegler Road Location: Fort Collins, Colorado EEC iProject#: 1122052 Date: June 2012 SWELL/CONSOLIDATION TEST RESULTS Material Description: Brown Sandy Lean Clay(CL) Sample Location:Boring 2, Sample 1, Depth 4' Liquid Limit: 31 Plasticity Index: 15 Passing#200: 58.8% Beginning Moisture: 9.4% Dry Density: 120.6 pcf Ending Moisture: 15.3% Swell Pressure: 4000 psf Swell @ 500: 2.4% 10.0 8.0 - 6.0 4.0 2.0 w E a> 0.0 m a - 2.0 Water Added 4.0 0 co N c -6.0 U 8.0 10.0 0.01 0.1 1 10 Load(TSF) Project: 5305 Ziegler Road Location: Fort Collins, Colorado j Project#: 1122052 E EC Date: June 2012 SWELL /CONSOLIDATION TEST RESULTS Material Description: Brown Sandy Lean Clay(CL) Sample Location:Boring 3, Sample 1, Depth 4' Liquid Limit: -- Plasticity Index: -- Passing#200: -- Beginning Moisture: 11.1% Dry Density: 111.7 pcf Ending Moisture: 19.4% Swell Pressure: 4400 psf Swell @ 500: 4.5% 10.0 8.0 - 6.0 e 4.0 2.0 -- g 0.0 m a - 2.0 Water Added 4.0 0 0 w o -6.0 U 8.0 10.0 0.01 0.1 1 10 Load(TSF) Project: 5305 Ziegler Road Location: Fort Collins, Colorado EEC )Project#: 1122052 Date: June 2012 SWELL/CONSOLIDATION TEST RESULTS Material Description: Brown/Grey/Rust Claystone/Siltstone/Sandstone Sample Location:Boring 3, Sample 6, Depth 29' Liquid Limit: 48 Plasticity Index: 27 Passing#200: 93.1% Beginning Moisture: 17.6% Dry Density: 111.5 pcf Ending Moisture: 20.3% Swell Pressure: 7500 psf Swell @ 500: 2.7% 10.0 8.0 6.0 a> w 4.0 2.0 - c 2 0.0 O. 2.0 Water Added 0 - 4.0 7 0 N o -6.0 0 8.0 10.0 0.01 0.1 1 10 Load(TSF) Project: 5305 Ziegler Road Location: Fort Collins,Colorado Project#: 1122052 EECDate: June 2012 V. SWELL/CONSOLIDATION TEST RESULTS Material Description: Brown Sandy Lean Clay(CL) Sample Location:Boring 4, Sample 1, Depth 4' Liquid Limit: -- Plasticity Index: -- Passing#200: -- Beginning Moisture: 10.4% Dry Density: 118.6 pcf Ending Moisture: 15.6% Swell Pressure: 5200 psf Swell @ 500: 4.1% 10.0 8.0 6.0 a) co 4.0 2.0 c a - 2.0 Water Added 4.0 0 v o o -6.0 U 8.0 10.0 0.01 0.1 1 10 Load(TSF) Project: 5305 Ziegler Road Location: Fort Collins, Colorado Project#: 1122052 Date: June 2012 CTL I THOMPSON I N C O ! P O A T D ECOLOGICAL CHARACTERIZATION STUDY 5305 ZIEGLER ROAD Prepared for: Architecture West, LLC 4710 South College Avenue Fort Collins, Colorado 80525 Attention: Mr. Stephen Steinbicker CTL I T Project No. FC05742.000 May 31, 2012 351 Linden Street,#140 I Fort Collins, Colorado 80524 I Telephone:970-206-9455 T TABLE OF CONTENTS 1.0 INTRODUCTION 1 2.0 SITE DESCRIPTION 1 3.0 ECOLOGICAL CHARACTERIZATION STUDY 2 3.1 Wildlife 2 3.2 Wetlands 3 3.3 Prominent views 3 3.4 Significant native trees or other on-site vegetation 3 3.5 Bank, shoreline, high water mark 3 3.6 Sensitive and specially valued species 4 3.7 Special habitat features 4 3.8 Wildlife migration corridors 4 3.9 General ecological functions 4 3.10Timing of development in relation to ecological character 4 3.11 Measures needed to mitigate adverse impacts on natural habitats and features 5 4.0 CONCLUSIONS AND RECOMMENDATIONS 5 REFERENCES FIGURE 1 — 5305 ZIEGLER ROAD GENERAL LAND COVER TYPES FIGURE 2— 5305 ZIEGLER ROAD DRAFT DEVELOPMENT PLAN APPENDIX A—SITE PHOTOGRAPHS 1 1.0 INTRODUCTION This report documents the evaluation of habitat conditions within the proposed 5305 Ziegler Road Multifamily/Mixed Use Development in Fort Collins, Colorado. The report was prepared in accordance with Section 3.4.1 (D)(1) of the Land Use Code of the City of Fort Collins regarding the preparation of an Ecological Characterization Study (ECS) Report. An ECS is required as the site is within 500 feet of McClelland's Creek, a known natural habitat. McClelland's Creek is a tributary to the Fossil Creek Reservoir. 2.0 SITE DESCRIPTION The proposed 5305 Ziegler Road Multifamily/Mixed Use Development encompasses approximately 4 acres and is located on the west side of Ziegler Road approximately 3/4 mile south of Harmony Road (Figure 1). The site extends about 700 feet north to south and 230 feet east to west. The site is bounded to the north by development, to the east by Ziegler Road, to the south by McClelland's Creek, and to the west by residential development and detention ponds. The legal description of the property is a portion of the NE '/4 of the SE '/4 of Section 5, Township 6N, Range 68W, 6th Principal Meridian. The site was visited on November 17, December 14, and December 16, 2011 by Ms. Georgia Doyle, a CTL biologist, to perform an ecological assessment and to map the edge of the McClelland's Creek riparian area. During the site visits, most of the vegetation trees, shrubs, forbs, and grasses)was dormant but dominant plant species were generally identifiable. The current land cover types on the site include the McClelland's Creek riparian area, a small area of upland plains shrubland adjacent to McClelland's Creek, a disturbed area with a gravel parking area and associated outbuildings, and a residence and outbuildings surrounded by lawn grasses/weeds and established trees (Figure 1). Photographs of the site are provided in Appendix A. General characteristics of the identified land cover types are summarized as follows: McClelland's Creek riparian area — The creek and riparian area cover an area of about 0.25 acre in the southernmost portion of the property. The creek is densely vegetated with cattail (Typha latifolia) with some areas of the open water supporting the non-native and widespread watercress Nasturtium officinale). Other plants growing within the riparian/wetland area include bulrush (Scirpus microcarpus), sedges (including Carex nebrascensis and C. praegracilis), and threesquare bulrush (Scirpus pungens). Along the bank there are a few small diameter (<6" diameter at breast height)cottonwood (Populus sp.)that were likely planted as part of a revegetation effort. Upland plains shrubland adjacent to McClelland's Creek — The riparian area (dominated by cattail and sedges) abruptly shifts to upland grass species with change in elevation. This upland vegetation covers about 0.2 acre. The bank supports a few shrubs (likely planted as part of revegetation effort) and mixed grasses and forbs. The shrubs include a red-osier dogwood (Corpus sericea) and a few golden currant (Ribes aureum) on the 5305 ZIEGLER ROAD,FORT COLLINS,CO 1 ECOLOGICAL CHARACTERIZATION STUDY CTL I T PROJECT NO.FC05742.000 F lower bank and a few rabbitbrush (Chrysothamnus nauseosus) and yucca Yucca glauca) on the upper bank. Grasses noted include the native species indiangrass (Sorghastrum nutans), western wheatgrass Pascopyrum smithii), sideoats grama (Schizachyrium scoparium), and blue grama (Bouteloua gracilis), and the non-native species smooth brome Bromus inermis), cheatgrass (Bromus tectorum), and crested wheatgrass Agropyron spicatum). Non-native kochia (Bassia scoparia) is also present. Disturbed area —The disturbed area covers an area of about 2 acres and includes an unvegetated gravel parking area and a few buildings. The area is fenced. Kochia and other non-native species occur around the edges of the compacted unvegetated parking area. One cottonwood occurs adjacent to Ziegler Road at the entrance to the parking area. Residence and surroundings—The residence, outbuildings, and associated yard cover approximately 1 acre. Trees/shrubs within the area include a row of non-native Siberian elm along the western boundary, a row of non- native Russian olive along the northern boundary, and a hedge of lilac along the eastern boundary (Ziegler Road). The trees on the property are discussed further in Section 3.4. The yard vegetation includes bare ground and lawn grasses with common weeds including kochia, bindweed, mallow, and dandelion. 3.0 ECOLOGICAL CHARACTERIZATION STUDY The elements of the Ecological Characterization Study are summarized in this section in the order listed in Section 3.4.1 (D)(1) of the Land Use Code. 3.1 Wildlife Wildlife observed during field visits to McClelland's Creek included a pair of mallards in the creek, unidentified songbirds in the rabbitbrush adjacent to the creek, and an American kestrel and red-tailed hawk in the vicinity. Wildlife sign included coyote droppings and rabbit droppings adjacent to the creek. A variety of songbirds likely use the area year- round. Mammal species likely to use the area include mule deer, coyote, raccoon, fox, striped skunk, mice, and non-native fox squirrels. In itself, the site provides relatively low wildlife value due its small size, previous disturbance, and limited food and cover provided by the sparse trees and shrubs. The primary wildlife value of the site is likely in providing connectivity with the McClelland's Creek corridor. Wildlife observed associated with the established trees of the residence area included a pair of great horned owls in the row of Siberian elm along the western property boundary. Great homed owls generally nest in abandoned tree nests built by raptors or corvids (e.g., crows and ravens) (Ehrlich et al. 1988), which build nests out of sticks. A small nest built of sticks was present in one of the Siberian elm trees on the site. Great homed owls can nest as early as late January with peak egg laying occurring mid March (Kingery 1998). The stick nest should be checked in February/March for signs of use by the owls. Also 5305 ZIEGLER ROAD,FORT COLLINS,CO 2ECOLOGICALCHARACTERIZATIONSTUDY CTL I T PROJECT NO.FC05742.000 observed foraging within the Siberian elm trees and underbrush were dark-eyed juncos and black-capped chickadees, typical winter songbirds for Fort Collins. A variety of songbirds likely use the area year round. Wildlife sign observed included rabbit droppings. 3.2 Wetlands The general boundary of the wetland or riparian area is shown on Figure 2. The boundary represents the contact of wetland plants (sedges)and upland grass species. The boundary was flagged on December 14, 2012 and subsequently surveyed. The boundary corresponds with the elevation contours. McClelland's Creek is considered a water of the U.S. and is regulated by the Army Corps of Engineers. Wetlands are present along McClelland's Creek. However, no wetlands or waters of the U.S. will be impacted by the proposed development as the development, including temporary impacts associated with grading and landscaping, intentionally provides a buffer for the creek and wetlands. Further, the structures are set back from the wetland features due to floodplain buffers. As required by the City of Fort Collins Land Use Code, an undeveloped buffer will occur between McClelland's Creek and the planned structures (Figure 2). No proposed temporary or permanent impact to regulated wetlands or waters of the U.S. are proposed in this project. 3.3 Prominent views The prominent views from this site include the Rocky Mountains to the west, the open space associated with McClelland's Creek, and the open space and Fossil Ridge High School to the east. The proposed structures should not impact the view of the Rocky Mountains from Ziegler Road or McClelland's Creek. 3.4 Significant native trees or other on-site vegetation Significant trees are defined in the Land Use Code as trees with a diameter at breast height (DBH)of over six inches. Certain species are considered nuisance species and are not designated as significant regardless of DBH. Mr. Tim Buchanan, City Forester documented the significant trees on the site on January 11, 2012. Approximately 15 trees on the site were designated as significant. The significant trees include one cottonwood female) on Ziegler Road adjacent to the current curbcut leading to the gravel parking area and about 100 feet north McClelland's Creek. The current development plans call for protecting this tree. Significant trees associated with the residence in the northern part of the site included Colorado blue spruce, green ash, cottonwood, hackberry, Austrian pine, and pinyon pine. Also present on the site are Siberian elm and Russian olive, trees considered nuisance species and not considered significant. The significant trees will either be protected or mitigated. Mitigation for all trees proposed for removal will be transplanting or replacing in accordance with Land Use Code Standards in consultation with the City Forester. 3.5 Bank, shoreline, high water mark The bank along McClelland's Creek appears to control flow. The bank height is approximately 5 feet above the level of McClelland's Creek. In the current development plan, the creek bank is not affected. The proposed development plan calls for maintaining the existing stream bank. A waiver of the requirement for onsite detention will be requested for this development due to its proximity to McClelland's Creek; however, water 5305 ZIEGLER ROAD,FORT COLLINS,CO 3 ECOLOGICAL CHARACTERIZATION STUDY CTL I T PROJECT NO.FC05742.000 quality measures will be provided at various locations within the development and may include the buffer area between McClelland's Creek and the proposed structures. 3.6 Sensitive and specially valued species There are no known occurrences or habitat for sensitive and specially valued species on the site. Species of concern in Larimer County include the Preble's meadow jumping mouse (Zapus hudsonius preblei), Ute lady's tresses orchid (Spiranthes diluvialis), and Colorado butterfly plant (Gaura neomexicana ssp. coloradensis), all of which are associated with riparian/wetland areas. According to the U.S. Fish and Wildlife Service (Misztal 2011 pers. comm.), all trapping for the Preble's meadow jumping mouse in Fort Collins has been negative. Additionally, the habitat on McClelland's Creek is poor quality for the mouse. Based on the poor habitat conditions and the negative trapping data, it is our professional opinion that Preble's does not occur on the site and development of this project will not affect Preble's adversely. Similarly, it is our opinion that the Ute lady's tresses and Colorado butterfly plant do not occur on the site. The closest known occurrences of these plants are near the northwest boundary of Fort Collins (orchid) and on Soapstone Prairie Natural Area near the Wyoming border (butterfly plant). Additionally, these plants would occur in an undisturbed setting and habitat restoration has occurred on McClelland's Creek. Other plant and animal species included in the Colorado Natural Heritage Program tracking list are not known to occur in the vicinity. 3.7 Special habitat features The site does not contain any special habitat features. 3.8 Wildlife migration corridors McClelland's Creek likely serves as a wildlife migration corridor. The current development plans do not call for development along McClelland's Creek and allow a buffer; therefore, the proposed development should not affect the functioning of McClelland's Creek as a wildlife corridor. 3.9 General ecological functions General ecological functions of McClelland's Creek and the associated riparian area include flood control, groundwater recharge, wildlife habitat, water quality improvement, and open space. The general ecological functions of the site are expected to be improved in the process of development of the site. The fence around the disturbed area will be removed and the area between McClelland's Creek and the structures will be revegetated with native species. The buffer area between McClelland's Creek and the structures will provide topographic and vegetative structure to an area that is currently a gravel parking area. The design and revegetation of the buffer area will take into account the guidance provided in the City of Fort Collins Landscape Design Standards and Guidelines for Stormwater and Detention Facilities dated November 5, 2009. 3.10 Timing of development in relation to ecological character The primary concern for the timing of development is protection of nesting birds. Under the Migratory Bird Treaty Act of 1916, it is unlawful to pursue, hunt, take, capture, kill, or sell 5305 ZIEGLER ROAD,FORT COLLINS,CO 4ECOLOGICALCHARACTERIZATIONSTUDY CTL I T PROJECT NO.FC05742.000 birds. This includes the taking of feathers and nests of migratory birds. If tree removal or construction commences during the bird breeding season, a survey for active nests should occur and nests should be avoided until activity ends. In addition, CDOW provides recommended guidelines for seasonal buffers for nesting raptors. The breeding season for most migratory birds is between March and August. As discussed in Section 3.1, the nesting season for great horned owls is earlier in the year. The timing of tree removal in the northern portion of the property needs to be timed to avoid disturbing nesting species. Because the McClelland's Creek area is not proposed for development or disturbance, the timing of development is not a concern in this area. 3.11 Measures needed to mitigate adverse impacts on natural habitats and features There are no known impacts to natural habitats or features on the site. The permanent impact will occur on previously disturbed areas primarily consisting of a gravel parking area, buildings, and non-native plantings. Measures to improve the site include creation of a detention basin or possibly, low impact development bioswales, that will provide a buffer between McClelland's Creek and the proposed structures. The buffer area will be vegetated with native plants. The proposed construction period is not yet known. If construction or tree removal is proposed to begin during the potential bird nesting periods, a nest search is recommended within two weeks prior to the start of construction or tree removal to avoid Migratory Bird Treaty Act infractions. Construction Best Management Practices would be used to mitigate any sedimentation of McClelland's Creek. 4.0 CONCLUSIONS AND RECOMMENDATIONS It is CTL's professional opinion that no significant ecological resources will be adversely impacted on this site. The primary concern in our opinion is timing of the construction and removal of trees to avoid disturbing nesting birds. The development plan is consistent with the intent of the Land Use Code. Furthermore, the site design offers features to enhance the ecological functions and values of the site. We ask that you review this ECS with the draft development plan submittal shown in Figure 2 to ensure that the performance standards for this project are achieved. If you have any questions about this ECS or would like to discuss this project further, please feel free to contact us. 5305 ZIEGLER ROAD,FORT COLLINS,CO 5 ECOLOGICAL CHARACTERIZATION STUDY CTL I T PROJECT NO.FC05742.000 F Respectfully submittted, CTL I THOMPSON, INC. Reviewed by: Georgia A. Doyle Melissa Chalona, P.E. Environmental Scientist/Biologist Environmental Department Manager 2 copies sent) REFERENCES Ehrlich, P.R., D.S. Dubkin, and D. Wheye. 1988. The Birder's Handbook, A field guide to the natural history of North American birds. Simon and Schuster, Inc. New York. 785 pp. Kingery, H. (ed.). Colorado Breeding Bird Atlas. 1998. Colorado Bird Atlas Partnership. 636 pp. Misztal, A. 2011. Email communication from Adam Misztal, U.S. Fish and Wildlife Service, Lakewood, Colorado to Georgia Doyle, CTL Thompson, Inc. November 7. 5305 ZIEGLER ROAD,FORT COLLINS,CO 6ECOLOGICALCHARACTERIZATIONSTUDY CTL I T PROJECT NO.FC05742.000 i.:,'.1_NCL AND SURROUNDINGS V Y U VI'!t t--“,..... I ' 1. outimby 4f,* I 0.,, SABER CAT DR. COUNTY FAIR LN. mo t Q t' .' r ti,, ,.• D 0 T DIS1 URBED AREA IR 1 i ti i i R i UPLAND PLAINS 1 SHRUBLAND MCCLELLANDS CREEK RIPARIAN AREA it I a fj J w N re 4 SAGE CREEK RD. cir APPROXIMATE E.HARMONY RD. O SCALE: 1"= 120' VICINITY MAP 0' 60 20 FORT COLLINS AREA NOT TO SCALE w 5305 Ziegler Road Ci w ROCK General Landa ^ CREEK DR. o ccm o AO SITE Cover Types ARCHITECTURE WEST,LLC m r 5305 ZIEGLER ROAD FIGURE 1 CTL I T PROJECT NO.FC057G2.000-210 6 RIVER PASS RD. I' Ii i I'Iz I ?1 I 1 .G i 9t, I `' a FOSSIL I'1 °L 1 I`,\, '/ _, - RID 6 E l — III H 16 H mow 'c; - = ‘\\\\" I `.4 S G H O O L U.)17\PI .'—',___\_. r_____ ,\ .. . „ ,, ,„ 1,,. i„ ‘,,, r, „,‘ s..„, , ,, 4,.. 22._ ....,::„. . .,......, i , . . z t l . I. 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