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Home My WebLink About20071137.tiff =HI SHANNON &WILSON, INC. SEATTLE RICMUIID RORTUIND GEOTECHNICAL AND ENVIRONMENTAL CONSULTANTS ANCHORAG DE DENVER SAINT LOUIS June 19, 2006 Carter Burgess 707 17th Street,Suite 2300 Denver, Colorado 80202 Attn: Mr. Raymond Hamilton RE: GEOTECHNICAL REPORT,LONE TREE WASTEWATER TREATMENT PLANT FACILITIES IMPROVEMENT PROJECT,GILL, COLORADO Enclosed is our geotechnical report for the above-referenced project. This report presents the results of our field exploration program and our conclusions and recommendations for the proposed facility. We appreciate the opportunity to be of service to you on this project. If you have any questions, or require further information,please contact me at 303-825-3800. Sincerely, SHANNON & WILSON,INC. Grego ' . Fischer, Ph.D., P.E. 1 - resident GRF/grf Enclosure: Geotechnical Report HO BLAKE STREET, SUITE 150 DENVER COLORADO 80202 PHONE 303.825.3800 23-1-01114-001 FAX 303.825-3801 shannonwilsor Corn 2007-1137 SHANNON&WILSON,INC. TABLE OF CONTENTS Page 1.0 INTRODUCTION 1 2.0 PROJECT DESCRIPTION 1 3.0 SITE DESCRIPTION 2 4.0 REGIONAL GEOLOGY 3 5.0 FIELD EXPLORATION AND LABORATORY TESTING 4 6.0 SUBSURFACE CONDITIONS 6 7.0 GEOLOGIC HAZARDS 7 7.1 Seismic Hazards 7 7.2 Swell Susceptible Soil and Bedrock 8 7.3 Collapsible Soil 8 8.0 CONCLUSIONS AND RECOMMENDATIONS 9 8.1 Seismic Parameters 9 8.2 Excavation and Support 9 8.2.1 Temporary Excavation Slopes 9 8.2.2 Temporary Excavation Support Systems 10 8.2.3 Excavation 11 8.2.4 Permanent Slopes 12 8.3 Structures 12 8.3.1 Foundation and Slab Recommendations 12 8.3.1.1 Secondary Clarifier 14 8.3.1.2 Aerobic and Anoxic Cells 15 8.3.1.3 Secondary Clarifier Splitter Structure 17 8.3.1.4 Process Building 18 8.3.2 Lateral Earth Pressures and Resistance to Lateral Loads 19 8.3.3 Backfill Placement and Compaction 20 8.4 Site Drainage 22 8.5 Sulfates and Corrosion 22 9.0 CONSTRUTION CONSIDERATIONS 23 9.1 Wall Footing and Slab Subgrade Preparation 23 9.2 Plan Review and Construction Observation 23 v-1-01114-001-RI or.aa« 23-1-01114-001 TABLE OF CONTENTS (cont.) SHANNON&WILSON,INC. 10.0 LIMITATIONS 24 LIST OF FIGURES Figure No. I Vicinity Map 2 Site and Exploration Plan 3 Generalized Subsurface Profile A-A' LIST OF APPENDICES Appendix A Field Explorations B Laboratory Test Results C Important Information about Your Geotechnical Report v-1-01i14-001-RI Draftdoc 23-1-01114-001 SHANNON&WILSON.INC. GEOTECHNICAL REPORT LONE TREE WASTEWATER TREATMENT PLANT FACILITIES IMPROVEMENT PROJECT GILL, COLORADO 1.0 INTRODUCTION This report presents geotechnical engineering recommendations for an expansion of the Lone Tree Wastewater Treatment Plant facility in Gill, Colorado. The report summarizes our subsurface explorations, laboratory testing and geotechnical engineering studies,and presents conclusions and recommendations for design of the structures. Our services were conducted in general accordance with our proposal to Carter Burgess, dated April 28,2006, as authorized on May 1,2006. 2.0 PROJECT DESCRIPTION Our understanding of the project is based on preliminary plans provided by Carter-Burgess(CB) and our discussions with representatives of CB. The project consists of additions to the existing treatment facility,including new aerobic and anoxic cells,two secondary clarifiers (of which only one the east one is being designed at this time and is discussed in this report), a process building and associated piping, and splitter boxes (Figure 2). The aerobic and anoxic cells will be open basin cast-in-place concrete structures with dimensions of approximately 440 feet by 112 feet. The structure will be divided into four compartments with concrete dividing walls along the length that make up the four cells. The walls of the structure will be about 16 feet high,which will allow 1.5 feet of freeboard, and supported on strip footings. The base slab(approximately 8-inches-thick)will be isolated from the wall footings,such that they can move differentially. A finished floor elevation (FFE)of 4,640 feet is planned. We understand that this elevation is at or slightly below the existing lagoon bottom. CB estimated a typical unbalanced load distribution on the wall footings for the cell structures to be trapezoidal. Contact pressures are estimated to range from a minimum of 1,500 pounds per square foot (psi) to a maximum of 3,000 to 4,000 psf Settlement tolerances of 1-inch total and Vi-inch differential across the cells were specified verbally by CB. 24.1-0114-00I-RI or,ftdor 23-1-01114-001 1 SHANNON&WILSON.INC. The east secondary clarifier will be about 80 feet in diameter and will be of similar construction as the cells,except that the walls will not be isolated from the base slab. The walls of the clarifier will be about 16.5 feet high,which will allow 1.25 feet of freeboard. The clarifier will be supported on a mat foundation with a FFE of 4,636.25 feet. The mat will be thickened under the walls to account for the higher stresses imposed on the mat in these areas. Settlement tolerances of 1/2-inch total and %4-inch differential across the clarifier were specified verbally by CB. We understand that the future west secondary clarifier would be located west of the existing western-most clarifier. Recommendations are not included for this secondary clarifier in this report as no borings were completed in the area. However, for preliminary evaluation and cost estimating purposes,we anticipate that foundation support for the west secondary clarifier will be similar to that of the east secondary clarifier. The process building(blower/lab/administration) will be one-story with approximate dimensions of 58 feet by 51 feet. There will be a I2-foot-deep basement under the southern one-half. A similar depth wet well will be located adjacent to the basement in the southwest corner of the structure. Cast-in-place concrete basement walls and above-ground masonry block upper walls are planned. The main floor FFE is planned around 4,650 feet, with the basement at about 4,638 feet. Wall loads are anticipated to be on the order of 4 kips per foot and the slab load is anticipated to be about 250 psf. Settlement tolerances are 1-inch total and 'A-inch differential. The secondary clarifier splitter will be a cast-in-place concrete structure about 12 to 16 feet square with a FFE of about 4,642 feet. Settlement tolerance for this structure was specified by CB to be 'A-inch total and %4 -inch differential specified. All of these structures will be subjected to lateral hydrostatic and earth pressures. Light to moderate gravity loads are anticipated. 3.0 SITE DESCRIPTION The site is located in Gill, Colorado, approximately six miles east of Greeley(Figure I) and northeast of the confluence of Lone Tree Creek and the South Platte River. A plaque on an existing building indicates that the current facility was dedicated in 1973. The surrounding topography is relatively flat. The treatment site is higher than the surrounding land and appears .0^ 23-1-01 114-001-RI Draft doe 23-1-01114-001 2 SHANNON&WILSON,INC. to have been filled. At the proposed addition, the site appears to be about 30 feet higher than the drainage way of Lone Tree Creek. The improvements are planned to be located north of the existing Aerated Lagoons #1 and 2, extending into the existing Aerobic Lagoon #1 (Figure 2). This area is relatively flat and consists mostly of drive lanes surfaced with gravel; the boundary of Aerobic Lagoon #1 is rip- rapped with concrete and asphalt pieces. In addition to the lagoons,two clarifier structures and a concrete building (pump station) are located in the area of the proposed improvements. We understand that the existing lagoons are lined. We anticipate that existing facilities/structures may be affected by the proposed construction. In particular,the proposed secondary clarifier is planned about 20 feet (edge-to-edge) from the existing easternmost clarifier and 5 feet from the landside toe of the embankment of the existing Aerated Lagoon #2. CB indicated that drawings of the existing clarifier show a FFE of 4,637.75 feet, which is approximately 1.5 feet above the proposed secondary clarifier. The drawings do not suggest any deep foundation support of the clarifier and do not provide any information about whether or not subgrade improvements were made prior to construction. We understand that this clarifier has performed satisfactorily,with little tilt (differential settlement)of the structure. We understand that the existing clarifier can be partially unloaded (excavated) on its east side such that shoring is not anticipated along this side of the proposed clarifier. However, shoring will likely be required along the south side of the new secondary clarifier because of the presence of the existing Aerated Lagoon#2. 4.0 REGIONAL GEOLOGY Based on geologic mapping in and around the study area by Tweto(1980) and Colton (1978), relict channel and floodplain deposits of the Broadway or Louviers alluvium underlie the project area. These deposits may include layers of gravel, sand, silt,and clay. As indicated by geologic mapping a few miles west of the site, a thin layer of windblown silt and sand a few feet thick may be present above the alluvium. Below the surficial deposits,bedrock of the Laramie Formation is present. In the project area, the Laramie Formation consists of interbedded layers of sedimentary fine sandstone, siltstone, and claystone. 23-1-01114-OOLRI DNf.doc 23-1-01114-001 3 SHANNON&WILSON.INC. 5.0 FIELD EXPLORATION AND LABORATORY TESTING Shannon & Wilson implemented a field exploration and laboratory testing program to evaluate subsurface soil,rock, and groundwater conditions at specific locations at the project site. The field exploration program included the drilling of nine boreholes, designated B-1,B-2, and B-4 through B-10(boring B-3 was eliminated during the drilling program). Temporary groundwater monitoring wells(piezometers)were installed in Borings B-2 and B-8. The monitoring wells may be used for groundwater monitoring during construction and should be abandoned by the contractor per local and state regulations when construction is complete. Following drilling,the • boring locations were marked and later surveyed by CB. The locations of the nine borings are shown on the Site and Exploration Plan, Figure 2. Borings B-1,B-5,B-9 and B-I0 were drilled by Vine Laboratories, Inc. of Denver, Colorado under subcontract to Shannon & Wilson. Borings B-I and B-10 were drilled on May 8,2006, using a track-mounted CME 45 drill rig. Boring B-1 was advanced to a depth of 51.5 feet with 71/4-inch outside-diameter hollow stem auger and Boring B-I 0 was advanced to a depth of 41 feet using 4%-inch outside-diameter solid stem auger. The maximum depth of Borings B-I and B-10 was limited by the available length of auger onsite on May 8, 2006. On May 9, 2006,two borings immediately adjacent to B-I and B-10 were advanced into bedrock and to total depths of 65.6 and 65.5 feet, respectively, using a truck-mounted CME 55 drill rig, and hollow-stem augers. On May 10,2006,Vine Laboratories drilled borings B-5 and B-9 with a truck-mounted CME 55 drill rig. Boring B-9 was advanced to a depth of 70.5 feet using 7%-inch outside- diameter hollow stem auger, and boring B-5 was advanced to a depth of 31.5 feet using 414-inch outside-diameter solid stem auger. Borings B-2,B-4, and B-6 through B-8 were drilled by Dakota Drilling, Inc. of Denver, Colorado under subcontract to Shannon &Wilson on May 11 and 12,2006. The borings were drilled using a truck-mounted CME 55 drill rig and 8%4-inch outside-diameter hollow-stem auger. The borings were advanced to depths ranging from 32.0 feet to 70.5 feet. Disturbed samples were obtained in conjunction with the Standard Penetration Test (American Society of Testing and Materials [ASTM] Designation D 1586) at about 5-foot depth intervals. The Standard Penetration Test (SPT)consists of driving a 2-inch outside diameter, split-spoon sampler a distance of 18 inches beneath the bottom of the borehole with a 140-pound hammer 23-1-01114-001-81 Dr 1, 23-1-01114-001 4 SHANNON&WILSON,INC. free-falling a distance of 30 inches. The number of blows required to advance the split-spoon through each of three 6-inch increments was recorded. The SPT resistance, or N-value, is defined as the number of blows required to drive the last 12 inches. If high penetration resistance prevented driving the total length of the sampler,the penetration resistance for the partial penetration was recorded. The N-values provide a means for evaluating the relative density or compactness of cohesionless (granular) soils and consistency or stiffness of cohesive (fine-grained) soils (see Figure A-1). Samples were also obtained using a 2-inch, inside diameter,modified California barrel sampler with liner tubes. The modified California sampler was advanced 12 inches by driving a 140- pound-hammer falling freely from a height of 30 inches and the penetration resistance, in blows per 12 inches,was recorded, similar to SPT techniques. These blowcounts are also shown on the boring logs (Appendix A). While these blowcounts are not exactly equivalent to SPT blowcounts, we assigned relative density and consistency descriptions based on the SPT blowcount system shown on Figure A-l. Representative portions of the split-spoon samples were placed in airtight plastic containers(for SPT samples)or sealed in the liner tubes (for modified California barrel samples) and transported to our laboratory for further observation and testing. The borings were coordinated (including utility locates) and observed by a geologist from Shannon & Wilson who collected soil/rock samples and prepared field logs of the borings. Visual classification of the samples was based on the classification systems shown in Appendix A for soil and rock (Figures A-1 and A-2, respectively). Individual boring logs are presented in Appendix A (Figures A-3 through A-11). These logs represent our interpretation of the contents of the field logs and the results of laboratory testing. Upon completion of drilling and sampling, groundwater levels were measured in the borings. Piezometers were installed in boreholes B-2, and B-8 immediately following drilling. Where piezometers were not installed,boreholes were backfilled with cuttings generated during the drilling process. Groundwater measurements made during drilling and measured in the piezometers thereafter are recorded on the individual boring logs in Appendix A, and are discussed further in Section 6.0 of this report. #' r3-l-0111 -OOI-Rl onn.doc 23-1-01114-001 5 SHANNON&WILSON.INC. Geotechnical laboratory tests were performed on selected samples retrieved from the borings to determine index and engineering properties of the materials encountered beneath the site. Laboratory testing included natural water content, total unit weight, grain size distribution, percent fines, swell, liquid and plastic Atterberg limits determinations,corrosion, and unconfined compression tests. The laboratory test results are presented in Appendix B. The natural water contents,Atterberg limits, and percent fines are also indicated on the individual boring logs in Appendix A. 6.0 SUBSURFACE CONDITIONS A generalized cross section illustrating subsurface conditions beneath the site is included as Figure 3. Based on the explorations, the subsurface conditions beneath the site generally consisted of approximately 52 to 54 feet of soil overburden overlying Laramie Formation bedrock. The soil overburden generally consisted of 13 to 18 feet (down to elevation 4,630 to 4,633 feet)of interbedded very soft to stiff, silty clay and clayey silt and loose to dense, clean to silty sand and sandy silt. Underlying these soils,we encountered approximately 35 to 40 feet of medium dense to dense,brown,clean to trace silty, fine gravelly sand with scattered stiff sandy clay seams. In the eastern borings(B-2, B-6 through B-8, and B-10), a layer of loose to medium dense,brown clean to silty sand with scattered clay layers was present between the upper silts and clays and the lower fine gravelly sands. This layer was up to 8 feet thick. Boring B-9 encountered the clean to trace silty, fine gravelly sand layer near the existing ground surface. The boring logs included in this report designate the upper 5 to 13 feet of overburden material as fill (exclusive of Boring B-9 where no apparent fill was observed). While it is unclear whether all of these upper soils are fill , our judgment is based on two factors. First, as previously discussed, the site exhibits apparent topographic alteration. Second, in some of the borings,the samples appeared disturbed and were classified as fill during field exploration. Underlying the soil overburden, the Laramie Formation bedrock encountered at the site generally consisted of very low strength, silty, fine sandstone and siltstone. Very low to low strength claystone was present at the bottoms of Borings B-4, B-7, and B-9. The contact between bedrock and the overlying alluvium was consistently encountered at depths of between 52 and 54 ^ n-i-mu4-ooi-Ri_Draft d« 23-1-01114-001 6 SHANNON&WILSON.INC. feet(elevations of 4,594 to 4,597 feet), indicating an approximately flat contact between soil overburden and the underlying bedrock. The borings also consistently encountered an approximately 10-foot-thick weathered zone at the top of the bedrock,distinguishable by a change in color from brown in the weathered zone to dark gray below, and accompanied by a slight observed increase in blow counts in some borings. Consistent with other locations along the Front Range, the majority of the bedrock encountered in the borings was found to be very dense and hard when considered as a lithified soil material. However,when compared with other types of bedrock using the International Society of Rock Mechanics (ISRM)classification of rock strength,the rock resembles a very low strength rock. Therefore, for completeness, the boring logs contain dual descriptions of the bedrock using the Unified Soil Classification System (USCS) and the ISRM classification system,where appropriate. Groundwater levels were measured during drilling in open borings and also in the piezometers installed in Borings B-2 and B-8. During drilling, groundwater was measured (and inferred from the depth to cave-in) at depths between 29 and 31 feet below the ground surface. Groundwater levels were measured in the two piezometers on May 19, 2006 at similar depths. The groundwater levels reported here reflect conditions at the time measured. Groundwater fluctuations are possible and are dependent on many factors, including seasonal variations and local precipitation. 7.0 GEOLOGIC HAZARDS 7.1 Seismic Hazards Colorado is comprised of areas of low to moderate potential for damaging earthquakes. Unfortunately, it is not possible to accurately estimate the timing or location of future major earthquakes, because the occurrence of major earthquakes is relatively infrequent and the historical earthquake record in Colorado is short(about 130 years). Based on a 1999 publication by the Colorado Office of Emergency Management, the nearest fault to the project site is in Golden, Colorado. Therefore, it is our opinion that the risk of fault rupture is low at the site. Liquefaction, lateral spreading, and dynamic settlement are factors that can negatively affect the stability and load carrying capacity of foundations and structures. However, because the peak .. 23-1.011FI-O0I.R1 Dn(I.doc 23-1-01114-001 7 SHANNON Fr WILSON,INC. horizontal ground acceleration(PGA) for this area of Colorado is low, there is a very low hazard potential associated with these seismic hazards and the design does not need to consider them. 7.2 Swell Susceptible Soil and Bedrock Swell susceptible soil and bedrock is common along the Front Range of Colorado. Because the site is relatively undeveloped it is difficult to rely on historic evidence of swell damage in the area to assess the risk to the planned structures. Instead,we reviewed a published swell potential map by Hart(1974),which indicates that the alluvial deposits generally have a low swell potential. To further classify the swell potential at the site, a swell test was preformed on a clayey soil sample obtained in Boring B-5. The tested sample did not exhibit swell when subjected to wetting under a surcharge pressure approximately equal to the field overburden pressure. Therefore, it is our opinion that the risk of swell-related damage in the near-surface soils is low. The Laramie Formation bedrock is known to be swell-susceptible in areas. However, because of its depth below the ground surface and the presence of a perched groundwater table above the deposit, it is our opinion that the potential for swell of this material is low. 7.3 Collapsible Soil Loess is a deposit of windblown silt and fine sand commonly cemented by clay minerals. Because of this cementation, deposits of loess can often be found standing nearly vertical and exhibit relatively high strengths when dry. However, when subjected to wetting, the cemented structure may break down causing a significant loss of strength, settlement, and deterioration of slopes. Loess deposits are common in semi-arid to arid regions, such as the plains and Front Range of Colorado. The available geologic maps covering the vicinity suggest potential windblown deposits of silt and sand in the area. Possible wind deposited material was also observed in the river bluffs immediately west of the project site. However, the near surface soils are predominantly cohesive and, therefore, the risk of collapse is low. In addition, the non-cohesive soils did not appear to exhibit a structure typical of the types of soils that can collapse when wetted. As such, it is our opinion that hazard potential associated with collapsible soils is low for this project. r 23-1-01114-001 RI_Draft doc 23-1-01114-001 8 SHANNON&WILSON.INC. 8.0 CONCLUSIONS AND RECOMMENDATIONS 8.1 Seismic Parameters Based on the blowcounts obtained in the borings and in accordance with the 2003 International Building Code(IBC), it is our opinion that the subsurface conditions are best represented by Site Class D. 8.2 Excavation and Support The FFE of the structures will be located up to 14 feet below the existing ground surface and have walls extending up to and above the ground surface. As indicated in Section 6.0,the near- surface materials encountered in the borings consisted of variable fill and interbedded native soils to a depth of 13 to 18 feet. These soils were classified as very soft to stiff, silty clay and clayey silt and loose to dense,clean to silty sand and sandy silt. The upper 5 to 15 feet of the subsurface soil was generally classified as fill and was softer and looser than the underlying soils. The groundwater table is located at a depth of about 30 feet below the existing ground surface and below the base of any excavation or proposed overexcavation. In general, the structures can be constructed to their proposed depth by either making an open excavation or using an excavation support system. Consistent with typical construction practice, ultimately it will be the Contractor's responsibility to provide a safe, stable means of constructing the structures. However, the Owner may dictate certain components of the system, depending on any limitations placed on excavation, based on the presence of adjacent structures and piping, for example. The following sections discuss excavation and support considerations for construction of this structure. 8.2.1 Temporary Excavation Slopes The safe slope for the excavation of subsurface materials depends on many factors, including: (1) the presence of groundwater; (2)the type, density, and shear strength of the subsurface materials; (3) the depth of excavation; (4)the presence of adjacent facilities; (5) surcharge loading adjacent to the excavation (including excavated material, existing dead or live loads, and construction equipment); and (6) time of construction. Considering these factors, unshored, temporary excavation slopes may be possible in areas around the site. When sloped excavations are used, slopes will likely be relatively flat because of the presence of the upper 23.101114-001-RI_Dnfl.doc 23-1-01114-001 9 SHANNON fiWILSON.INC. l weaker clays and loose sands. For cost estimating and planning purposes only, temporary excavations above the groundwater level will likely require slopes of 1.0 to 1.5 horizontal to 1.0 vertical (1.0- 1.5H:1 V), assuming an excavation depth of less than 20 feet. Consistent with conventional practice, the contractor should be responsible for the actual temporary excavation slopes, including methods,sequence, and schedule of construction. The Contractor is able to observe the nature and conditions of the subsurface materials encountered and should evaluate the factors discussed above. If instability is observed, slopes should be flattened or shored. All excavations should be accomplished in accordance with local, state, and federal safety regulations. 8.2.2 Temporary Excavation Support Systems In areas where site conditions preclude the use of temporary slopes, such as around the south side of the proposed secondary clarifier,temporary shoring should be used. Usually, in shored excavations in competent soils that extend to only moderate depths(up to about 30 feet), our experience has been that temporary, flexible support systems are the most economical, even when the cost associated with constructing the final structure walls within the excavation is r considered. Under these circumstances, permanent, rigid systems typically are more expensive because of the large initial construction cost. Based on our knowledge of the subsurface conditions at the site, sheetpiles may be the most economical temporary, flexible excavation support system for this project, although soldier piles and lagging and other systems should not be discounted. In our opinion,sheet piles would need to be driven into the dense sand (encountered in the borings below approximately elevation 4,630 to 4,633 feet). Because the sheetpiles would be relatively long and retaining relatively weak soils, a cantilevered system may not be possible in some areas. Further, deflections associated with cantilevered systems may not be tolerable on adjacent structures or ground. If additional lateral resistance is required,it could be achieved using interior bracing/rakers or tiebacks. Regardless of the shoring system used, its design should consider the potential for basal instability and heave. Recommended soil properties for the design of temporary shoring are provided below. Surcharge loading should be added to the lateral earth pressures, as appropriate. n-i-Ql ne-001-RI Draft doc 23-1-01114-001 10 SHANNON FWILSON,INC. PARAMETERS FOR DESIGN OF TEMPORARY SHORING SYSTEMS Elevation' Total Unit Generalized Soil Type' (feet) Weight2,pcf3 s c6, psf FILL(Soft to medium GS'—4,635 115 0 500 Stiff, silty CLAY) or (Loose, sandy SILT) 115 28 0 Stiff,sandy 4,635—4,630 120 0 1,000 silty CLAY or Medium dense,sandy SILT 120 30 0 Medium dense, 4,630-4,595 125 35 0 gravelly SAND Notes: 1. Generalized Soil Type and Elevation based on the borings 2. Total Unit Weight based on soils above the water table. Groundwater table of 4,620 feet should be assumed. 3. pcf: pounds per cubic foot 4. psf: pounds per square foot 5. Gt.: friction angle 6. c: cohesion 7. GS = existing ground surface The final selection of shoring type, temporary shoring design, and method of construction should be the responsibility of the Contractor. Further,it should be the Contractor's responsibility to monitor the stability of slopes or shored excavations and take corrective action if any potentially unstable conditions are encountered. 8.2.3 Excavation Construction of the structures will require excavation to depths of up to 20 feet below the existing ground surface. We anticipate that the soils to a depth of 20 feet can be excavated using conventional excavating equipment. We recommend that at least the last foot of excavation be accomplished using an excavating bucket that has a flat plate over the teeth. This will reduce the disturbance to .-. 73-I-OIIIJ-Op LRI Draft doc 23-1-01114-001 11 SHANNON&WILSON.INC. L foundation soils. A geotechnical engineer or geologist familiar with the subsurface conditions should observe all subgrades to confirm that the anticipated materials are encountered. It will be important for the contractor to avoid repeated construction traffic over the final subgrade by planning the work sequentially from one end to the other. If the foundation soils become loosened or disturbed during construction, they should be removed and replaced with an imported crushed gravel fill or recompacted in place. It will not be practical to stabilize the clay soils at the anticipated foundation depth because of their high moisture content and plasticity. If excavations are extended down into the relatively clean, gravelly sand layer,recompaction of disturbed soils may be effective. 8.2.4 Permanent Slopes We recommend that permanent cut and fill slopes be made at 3H:1 V or flatter. All slopes should be seeded and protected with erosion control blankets or covered with gravel, quarry spalls or riprap, as appropriate. 8.3 Structures 8.3.1 Foundation and Slab Recommendations In our opinion, the groundwater table is unlikely to rise above the FFE of the structures (the lowest FFE is proposed at elevation 4,636 feet). As such, it is our opinion that the structures do not need to be designed for buoyancy. Nevertheless,we recommend an exterior drain system around below-grade walls, as discussed later in this report, to reduce the potential for hydrostatic pressures to build up against walls. There are several feasible alternatives for support of the structures and to a certain extent the recommended foundation support system depends on the performance requirements of the structure and the Owner's tolerance for risk. We considered four alternatives for foundation support of the various structures, including(1) conventional footings and slabs on the native soils at the proposed FFE's discussed in Section 2.0, (2) conventional footings and slabs supported on the medium dense, native,gravelly sand below about elevation 4,630 feet (or on a properly compacted structural fill placed on top of this layer), (3) short foundation elements (compacted aggregate piers) that can transfer the load through overlying clays and silts to the medium dense, gravelly sand layer, and (4) deep foundation elements. ]3.401 114-001-RI Dr,adoc 23-1-01114-001 12 SHANNON&WILSON,INC. While feasible,it is our opinion that deep foundation elements are not an economical foundation system for this site. This is mainly because of the presence of a competent bearing layer(medium dense or denser, gravelly sand) at about elevation 4,630 feet, which can be reached with short foundation elements(compacted aggregate piers)or by overexcavation. In addition,deep foundations would likely consist of driven piles because of the presence of relatively clean sand layers and a high groundwater table that would make drilled shaft installation difficult. If driven piles are used, they would need to be driven into bedrock below about elevation 4,595 feet to take economical advantage of their capacity. A summary of our recommendations for the remaining three foundation types relative to the proposed structures are tabulated below. More specific recommendations for each structure are discussed in the following subsections. SHALLOW SHALLOW COMPACTED., FOUNDATIONS ON FOUNDATIONS IN AGGREGATE PROPOSED NATIVE SOILS AT' GRAVELLY SAND PIER STRUCTURE PLANNED GRADES (APPROX ELEV 4,630 FT) FOUNDATION SUPPORT' Secondary Not Recommended Recommended Not Recommended Clarifier Aerobic and Not Recommended for Feasible Recommended for Anoxic Cells Wall Foundations, Wall Foundations, Feasible for Slabst'2 Feasible for Slabs Secondary Feasiblela Feasible Feasible Clarifier Splitter Structure Process Feasible"2 Feasible Feasible Building 'Feasibility for foundation and slab support in the native soils are dependent on confirmation of subsurface conditions by making additional exploratons at the proposed structure locations within the existing lagoon. See discussion in text. 2If a shallow foundation is used,it will be critical that a geotechnical engineer or geologist be on site during excavation to identify the contact between the upper fill and the natural subgrade. All foundations must be supported on native soil below existing fill. See discussion in text. zs-t-mna-an-ai o,on.doc 23-1-01114-001 13 SHANNON&WILSON.INC. The native soils above elevation 4,630 feet and below the existing fill were interbedded and widely variable in both composition and relative density/consistency in the borings. As indicated in the above table, we have provided recommendations for shallow foundation support in these soils for most of the structures, assuming that subsurface conditions in the nearest boring(s)to each structure is applicable. However,these recommendations are contingent on additional subsurface exploration at the actual structure locations confirming the adjacent borings used in our analyses. This is important because the soils underlying the lagoon have not been consolidated as much as under the weight of the fill from the soils that were used to build up the site. As such, the underlying clay/silt soils beneath the lagoon could be significantly weaker and more compressible than the clay/silt represented by the adjacent borings. If the schedule will not permit this additional exploration or potential redesign,we recommend selecting a different foundation support alternative. If shallow foundations are used,they should be embedded below the zone of potential frost depth(at least 2.5 feet below the final ground surface). Mat foundations generally will perform more satisfactorily than individual spread footings because of their ability to span over localized soft/weak soil areas and to transfer load along the slab. We recommend mat foundations be used for those structures where shallow foundations will be used and either overexcavation or compacted aggregate pier support is not provided. 8.3.1.1 Secondary Clarifier In our opinion,the proposed structural mat (raft) foundation is appropriate for the clarifier. However,because of the strict settlement criteria for this structure(1/2 inch total and 1/4 inch differential across the clarifier),we recommend that the medium stiff to stiff silt and clay underlying the clarifier to a depth of about 18 feet (see Borings B-2 and B-8)be overexcavated to expose the medium dense to dense, gravelly sand layer. We estimate that this will require up to 4 feet of overexcavation. We understand that the slab will be designed by the structural engineer using soil springs (vertical modulus of subgrade reaction) to model the distribution of the load across the slab. The vertical modulus of subgrade reaction needed for this design is a function of the size and shape of the foundation. Based on the dimensions of the structure indicated in Section 33 01110.001 RI Oran doc 23-1-01114-001 14 SHANNON&WILSON,INC. 2.0,we recommend a coefficient of subgrade reaction of 50 pounds per cubic inch (pci)for average mat pressures of 3,000 psf or less. This coefficient of subgrade reaction value assumes that the clay/silt soils are overexcavated to expose the medium dense to dense, gravelly sand and any overexcavation is replaced with select granular fill (as discussed in Section 8.3.3). If the size of the loaded area changes,this value should be re-evaluated. Based on the size of the proposed structure, we estimate that total settlement of the slab could exceed the 1/2 inch criterion (see Section 2.0), especially if average slab pressures exceed the existing overburden pressure at the proposed slab elevation(about 1,800 psf). However, in our opinion, differential settlement across the clarifier slab should be on the order of the 1/4 inch criterion for a properly prepared foundation subgrade. We anticipate that settlement generally will occur as the load is applied. 8.3.1.2 Aerobic and Anoxic Cells In our opinion,there is a potential for differential and total settlement of the aerobic and anoxic cell walls that will exceed the criteria listed in Section 2.0 if the proposed foundation system is installed at the planned grades without modifying the underlying soils. This is mainly because at the higher elevation of these foundations there will be up to 10 feet of widely varying unconsolidated clay/silt soils under the foundations. In addition,because the wall footings are isolated from the slab,the bearing pressures under the walls generally will be higher than that for a structural mat foundation, unless very wide footings are placed, increasing the potential for both total and differential settlement. As a result,we recommend that the wall foundations either be supported on a compacted fill pad or short compacted aggregate pier foundation elements. For the former,the clay/silt soils would be overexcavated down to the medium dense to dense, gravelly sand (estimated elevation 4,630 feet) and replaced with select granular fill (Section 8.33)back to the proposed bottom of footing elevation. However, because of the potential depth of this overexcavation, we recommend the use of short foundation elements(compacted aggregate pier) as a means to support the wall foundations, as discussed below. Compacted aggregate piers are used to transfer loads to more competent bearing layers(in this case the medium dense to dense, gravelly sand layer encountered at about elevation 4,630 feet). There are several proprietary systems available, including Geopiers by the 13.I.oina.00i-RI D,and« 23-1-01114-001 15 SHANNON fiVVILSON.INC. Geopier Foundation Company, Inc. and vibro-replacement columns by Hayward Baker. Compacted aggregate piers are constructed by drilling an open or cased hole through the non- bearing layer and into the bearing layer. Small lifts of well-graded gravel are then placed in the hole and incrementally compacted using a beveled ram (Geopiers)or vibrated (vibro- replacement columns). With Geopiers,the compaction of each lift not only creates a dense material within the pier, but also increases the stress in the surrounding soil. For this project, the compacted aggregate piers would be constructed beneath the footings to provide positive underpinning support and increased bearing capacity. The compacted aggregate piers will have an additional advantage of decreasing the size of footings. According to the Geopier Foundation and Soil Reinforcement Manual,the capacity of a 30-inch-diameter Geopier is approximately 70 kips. A 24-inch diameter Geopier has a capacity of approximately 45 kips. The Structural Engineer should space the Geopiers or other compacted aggregate pier beneath the footings based on these capacities and the ability of the footings to span between Geopiers. Because of the proprietary nature of these foundation systems, the design is normally completed by the foundation system vendor. For design, the vendor should be given the net allowable bearing pressure of the strip footing(4,000 psf) and the settlement tolerances outlined in Section 2.0. As stated previously, assuming conditions in the borings drilled on land are similar to those in the lagoon, it is our opinion that the cell slabs can be supported approximately at the proposed grades. However, all existing fill soil should be overexcavated from beneath the cells and the subgrade should be proof-rolled by a fully loaded dump truck or equivalent to delineate any loose, soft,or yielding areas. Such areas should be overexcavated and replaced with select granular fill. If the Owner is unwilling to accept the risk of potential changes during construction based on completing explorations in the lagoon, the slabs can also be supported on widely-spaced compacted aggregate piers. For this condition, we recommend a net allowable bearing pressure of 1,000 psf(the weight of fluid in the cells on top of the slab) along with the settlement criteria in Section 2.0. For structural design, we recommend a coefficient of subgrade reaction of 12 pci, which is based on the relatively large dimensions of the slabs indicated in Section 2.0 and assumes the clay/silt soils are not overexcavated. If the size of the loaded area changes, this 23.101114-001-R i pon.dx 231-01114-001 16 SHANNON&WILSON.INC. value should be re-evaluated. In our opinion, it is not economical to overexcavate beneath the slab area. We anticipate maximum settlement of the slabs to be on the order of 1 inch if the slabs are supported directly on the unimproved clay/silt soils. Because these soils are cohesive,the settlement will be somewhat time dependent with approximately 75 percent of the settlement occurring within three months of load application with the remaining occurring within one year following loading. If the clay/silt soils are removed or compacted aggregate piers are used to support the slab,we estimate settlement will be about one-half of the above value and generally occur as the load is applied. 8.3.1.3 Secondary Clarifier Splitter Structure We understand that the secondary clarifier splitter structure will be supported on a mat foundation. Ideally,the mat would be designed to be filly compensated at the proposed FFE of 4,642 feet. However,because the splitter structure is located within the aerobic lagoon #1 and the existing ground elevation is only a few feet above the proposed FE,it will not be possible to design a fully compensating foundation. Boring B-4 indicates the presence of 8 feet of medium stiff fill overlying very stiff clay/silt below elevation 4,640 feet. Assuming the actual conditions under the splitter structure are similar to those at Boring B-4, and are confirmed by additional exploration, it is our opinion that a mat foundation can still be successfully used at this location. The mat foundation should bear on the very stiff clay or on a compacted pad of select granular fill material placed on top of the very stiff clay. All existing fill soils must be removed from beneath the foundation. For these conditions, we recommend designing the mat for a net allowable bearing pressure of 1,500 psf and anticipate total settlement of the mat foundation to be less than 1/2 inch with differential settlement of the mat to be on the order of 1/4 inch" About 75 percent of this . settlement is anticipated to occur within the first three months after the load is applied with the remainder generally occurring over the next year. If higher settlement(I inch total and 1/2 inch differential)could be accepted, the net allowable bearing pressure could be increased to 2,500 psi Alternatively, compacted aggregate pier elements may be used beneath the mat foundation to increase bearing capacity. 23-1-01110-001-RI DnRdoc 23-1-01114-001 17 SHANNON&WILSON.INC. For structural design, we recommend a coefficient of subgrade reaction of 35 pci,which is based on the dimensions of the structure indicated in Section 2.0. If the size of the loaded area changes,this value should be re-evaluated. 8.3.1.4 Process Building Similar to the splitter structure,the process building is located over a portion of the pond that has not been completely covered by site fill. However,Borings B-6 and B-7 suggest reasonable bearing materials below the fill layer. Provided these conditions can be confirmed at the actual structure location by explorations, we recommend that the structure be , supported on the native soils below this fill or on a recompacted pad of select granular fill that is placed on top of the native soils below any existing fill. We understand that strip footings are preferred to support the structure with an interior floating floor slab that is not loaded. Because of the potential for the near-surface soils to vary,we recommend consideration be given to using a fully compensated mat foundation similar to the splitter structure. For these conditions,we recommend designing the mat for a net allowable bearing pressure of 2,500 psf and anticipate total settlement of the mat foundation to be less than 1 inch with differential settlement of the mat to be on the order of 1/2 inch. About 75 percent of this settlement is anticipated to occur within the first three months after the load is applied with the remainder generally occurring over the next year. Compacted aggregate pier elements maybe used beneath the mat foundation to increase bearing capacity. For structural design of a mat foundation, we recommend a coefficient of subgrade reaction of 35 pci,which is based on the dimensions of the structure indicated in Section 2.0. If the size of the loaded area changes, this value should be re-evaluated. If it is desired to use conventional strip footings, such footings should be designed for a net allowable bearing pressure of 2,000 psf. For this pressure, we estimate that total and differential settlements should be on the order of 1 and 1/2 inch, respectively. Footings should be a minimum of 3 feet wide and embedded below the zone of potential frost depth (at least 2.5 feet below the final ground surface). Compacted aggregate piers could be used to increase the bearing pressure to 4,000 psf, similar to the aerobic and anoxic cell wall foundations, for the same settlement tolerances. n-1.OH 14-001-RI or4n.doc 23-1-01114-001 I8 SHANNON&WILSON.INC. If strip footings are used,we recommend that the floor slab be isolated from the footings and allowed to move differentially with respect to the building foundations. In addition, we recommend that footings for the southern half of the building,which will contain a basement level,be overexcavated to a depth of at least one footing width and be recompacted with select granular fill- Footings for the upper half will be on select granular fill that is used to backfill the overexcavated fill soils. The design of the structure should consider the possibility of differential settlement between that portion of the structure founded at depth and that portion founded near the ground surface. We recommend consideration be given to including a control joint that separates the structure at this location and allows for differential movement. In addition, some ground readjustment is expected after backfilling to the proposed finished floor grade. As such, we recommend including a minimum time period of one month after backfilling prior to construction of the upper level. 8.3.2 Lateral Earth Pressures and Resistance to Lateral Loads The earth pressures that will act on below-grade walls is directly dependent on the expected movement of a wall when it is subjected to soil loading. If a wall is rigid and unyielding or restrained, at-rest earth pressures will act on the wall. If a wall is allowed to move or rotate greater than 0.1 percent of the wall height, active earth pressures generally will develop on the wall. We recommend the following equivalent fluid densities be used for design of below grade walls, assuming flat backslope conditions. Yielding Walls(Active State): 35 pcf Non-Yielding/RestrainedWalls (At-Rest State): 55 pcf where pcf=pounds per cubic foot The above equivalent fluid densities do not include the influence of water pressure or surcharge loads. Regarding the former, drainage should be provided so that groundwater and associated water pressure do not build up behind the walls (see Section 8.3.3). Regarding the latter,walls should be designed for surcharge loads that are present within a zone behind the wall equal to the height of the wall. To obtain the horizontal surcharge pressure that will act on the 23-1-01114-001-R I_Dna doc 23-1-01114-001 19 SHANNON&WILSON,INC. walls, the vertical surcharge pressure behind the wall should be multiplied by 0.28 for yielding walls and 0.45 for non-yielding(and restrained)walls. The lateral pressures and coefficients presented in this report assume flat ground backslope conditions. If sloping backslopes are planned, the equivalent fluid densities and lateral pressure coefficients will increase. Lateral forces may be resisted by passive earth pressure acting against the buried portions of the structures(walls and foundations). To resist lateral loads,we recommend using the following parameters. Equivalent Fluid Density for Passive Resistance: 250 pcf Allowable Coefficient of Sliding Resistance: 0.35,with a maximum allowable frictional resistance of 500 psf The above passive soil resistance has been reduced by a factor of two to account for a factor of safety on ultimate soil strength and to account for limited lateral deflections of about 1/2 inch. The passive resistance assumes a horizontal ground surface in front of the wall or foundation and would decrease if the ground surface is sloping away from the front of the wall or foundation. It also assumes the walls and foundations are backfilled with structural fill,as specified in Section 8.3.3. The allowable coefficient of sliding resistance includes a factor of safety of 1.5 on the ultimate soil strength. 8.3.3 Backfill Placement and Compaction We recommend that a 12-inch-thick(minimum), clean granular layer be placed under all slabs to provide uniform support for the slab and to provide drainage beneath the slab. The layer should be hydraulically connected to the wall drainage material, which is discussed below. Structural fill should be used for backfill within a I H:1 V zone behind walls. Structural fill should consist of either on-site or native non-swell susceptible(free swell of less than one percent when tested at 500 psf surcharge pressure at its maximum dry density and optimum moisture content) granular material with less than 30 percent fines(material passing the U.S. Standard No. 200 sieve). In addition, the fines should have a maximum liquid limit of 30 and a plasticity index less than 10. We recommend a maximum particle size of three inches for 23- -01114-001-RI Draft.doc 23-1-01114-001 20 SHANNON&WILSON,INC. structural fill. Relatively clean imported structural fill will help facilitate backfilling and compaction, although typically at a higher unit cost. We do not recommend using the native sandy clay as structural backfill because of its weak properties, the need to dry the material to a moisture content suitable for compaction, and difficulty in obtaining compaction with conventional equipment. This material could be used as the relatively impermeable cap as discussed in Section 8.4. Structural fill should be placed in horizontal lifts, compacted to at least 92 percent of its Modified Proctor maximum dry density(ASTM D 1557), and be deemed to be in a dense and unyielding condition. Structural fill should be moisture treated to within 3 percent of optimum moisture content. The thickness of loose lifts should not exceed 12 inches for heavy equipment compactors and 6 inches for hand-operated compactors,but may be less depending on that required to obtain the above relative compaction. All compacted surfaces should be sloped to promote drainage and prevent ponding. Compaction of backfill adjacent to walls can result in higher lateral earth pressures against the wall. Heavy equipment should stay behind a line extending upward from the base of the walls at 0.5H:I V, or 3 feet from the wall, whichever is greater. The backfill within this zone should be compacted with hand-operated equipment. Where hand-operated equipment is used, the maximum lift thickness of fill should be reduced to 4 inches. Unless the structural engineer indicates differently,we recommend that the backfill around the structure be brought up in uniform horizontal layers. A drainage layer should be placed against the wall to reduce the potential for groundwater pressures to act against the wall. A collection system(such as a perforated pipe surrounded by a layer of pea gravel) and a discharge system (such as a sump pump)will be required to maintain a drained condition. The lateral earth pressures in Section 8.3.2 assume a drained condition behind the wall. Select granular fill should be used for replacement of any overexcavation beneath structures to provide suitable support and to reduce the long-term compressibility of these materials. It should meet the gradation for CDOT Class 6 fill and be placed in horizontal lifts, compacted to at least 95 percent of its Modified Proctor maximum dry density(ASTM D 1557), and be deemed to be in a dense and unyielding condition. Select granular fill should be moisture 23.1-0114-001-R I_Drafl doc 23-1-01114-001 21 SHANNON&WILSON.INC. treated to within 2 percent of optimum moisture content. The thickness of loose lifts should not exceed 12 inches for heavy equipment compactors and 6 inches for hand-operated compactors, but may be less depending on that required to obtain the above relative compaction. All compacted surfaces should be sloped to promote drainage and prevent ponding. 8.4 Site Drainage To control surface water, the ground surface should be sloped away from structures at a minimum of 10 percent in the first 10 feet, unless paved wherein the slope can be reduced to 2 percent. We also recommend placing a 6- to 12-inch-thick relatively impermeable soil cap(or asphalt)around structures to reduce infiltration of surface water into the ground. Roof downspouts should not be permitted to discharge into foundation drains or into backfill zones. Collected water should be directed away and downslope of the building or into a storm drain system. 8.5 Sulfates and Corrosion The clayey soils and bedrock in the greater Denver area are generally considered corrosive. To assist us in estimating corrosion potential, several samples of soils from the upper 15 feet of the borings were tested for pH, water soluble sulfates, chloride content, and resistivity. As indicated in Table B-1 (Appendix B), the concentration of water soluble sulfates measured in samples obtained from the exploratory borings were negligible to 325 ppm. Based on classifications as defined by the American Concrete Institute(ACI 318-02), the test results (Table B-1 in Appendix B)suggest a negligible to severe degree of sulfate attack on concrete exposed to these materials,with the higher end requiting Type V cement, a maximum water- cement ratio of 0.45, and a minimum compressive strength of concrete of 4,500 pounds per square inch (psi). The pH measured on samples of subsurface materials ranged from 7.7 to 8.1. Chloride levels are 4.5 to 157.5 ppm. ACl recommendations should be consulted for design of concrete in contact with soils. v-i-01II4-00f-RI Drmdo` 23-1-01114-001 22 SHANNON FIWILSON.INC. Finally, as shown in Table B-1,the minimum resistivity measured on samples of subsurface materials ranged from 10 to 61 ohm-m. These values suggest moderate to severe soil corrosivity. We recommend that a specialist in corrosion-resistance design review the results included in Table B-1 to determine the actual construction materials and methods based on the test results. 9.0 CONSTRUTION CONSIDERATIONS 9.1 Wall Footing and Slab Subgrade Preparation The allowable bearing pressure and modulus of vertical subgrade reaction values presented in this report are contingent on the following construction considerations: 1. Wall footing and slab subgrade excavations are cleaned of all fill, debris, and loose, soft, wet, or disturbed soil prior to placing base coarse and concrete. 2. Wall footing and slab excavations are kept free of water at all times. 3. Excavations for foundations and slabs are observed by a geotechnical engineer to evaluate the adequacy of the bearing stratum and to confirm that subsurface conditions at and below the bearing elevation are suitable for the design values given. 9.2 Plan Review and Construction Observation We recommend that we be retained to review the geotechnical aspects of the plans and specifications prior to bidding the work to determine that they are in accordance with our recommendations. While this step is often skipped in design document preparation, our experience is that the review can find discrepancies or misinterpretations and correct them before bidding, thus avoiding potential change orders during construction. Geotechnical design recommendations are developed from a limited number of explorations and tests. Therefore,recommendations may need to be adjusted in the field. To this end,we recommend that a construction observation and monitoring program be implemented for the project and that Shannon & Wilson be retained to monitor the geotechnical aspects of construction, particularly foundation support for the structures and any shoring construction. D-1-01110-001.R1 Drafl.doc 23-1-01114-001 23 SHANNON&WILSON.INC. This monitoring would allow us to determine that the work is accomplished in accordance with good construction practice and our recommendations. 10.0 LIMITATIONS This report was prepared for the exclusive use of HDR and the Swift&Company for specific application to the design of the structures at the locations indicated in this report. It should be made available to prospective contractors and/or the Contractor for information on factual data only, and not as a warranty of subsurface conditions, such as those interpreted from the exploration logs and presented in the discussion of subsurface conditions included in this report. The analyses,conclusions, and recommendations contained in this report are based on site conditions as they presently exist. We assume that the current explorations are representative of the subsurface conditions at the site; that is, the subsurface conditions everywhere are not significantly different from those disclosed by these explorations. If, during construction, subsurface conditions different from those encountered in the explorations or described in this report, are observed or appear to be present beneath excavations,we should be advised at once so that we can review these conditions and reconsider our recommendations where necessary. Unanticipated soil conditions are commonly encountered and cannot fully be determined by taking samples from borings. Such unexpected conditions frequently require that additional expenditures be made to attain properly constructed projects. Therefore, some contingency fund is recommended to accommodate such potential extra costs. Within the limitations of the scope, schedule and budget, the analyses, conclusions and recommendations presented in this report were prepared in accordance with generally accepted professional geotechnical engineering principles and practice in this area at the time we prepared our report. We make no other warranty, either express or implied. These conclusions and recommendations were based on our understanding of the project as described in this report and the site conditions as interpreted from the current explorations. The scope of our services did not include any environmental assessment or evaluation regarding the presence or absence of wetlands or hazardous or toxic materials in the soil, surface water, groundwater, or air, on or below the site, or for evaluation for disposal of contaminated soils or groundwater, should any be encountered v-1-Oil I4-OOI-Ripvadoc 23-1-01114-001 24 SHANNON&WILSON,INC. We have prepared Appendix C, `Important Information About Your Geotechnical Report,"to assist you and others in understanding the use and limitations of our reports. SHANNON &WILSON,INC. i • it mt. CCs 9: : .,,. = : 3446 C_. : . • F.:�..... . �ZCs\O' Kyle A. Kershaw,P.E. Gregory R. Fischer,Ph.D.,P.E. Senior Engineer Vice President KAK:GRF/ n-i-on14-001-RI Draftdoc 23-1-01114-001 . 25 ) A I A West PROPOSED AEROBIC ANOXIC CELLS I East PROPOSED PROCESS BUILDING I I 4680- _ _ _ PROPOSED SECONDARY ___ ._..__ .... _ - 4680 SEDDARY CLARIFIER SPLRTER -I SECONDARY CLARIFIERI- 1 vad.bb FlLL;Lobes, B-6 8-� B-1B Existing Ground Surface '.-SILT end to s IPrq.B S.) (Pub S) Leasedean toa dense, IPrq.12T 6I 4660- ril12R5) _..I L t_._. B _ ails curela slLT � 11.:9-12.1t-281.12.11--5L i 1PJ'J �e1h5AN__ I _ 4660 y very _ I (PM 66 {; I 0 ;pfi . —.. . I eelnTer&adeTm�maaf6aery eA le m 7 �I• . 7il ?' ;`moo_ ? —14640 .:Iv �? CLAYwith varying amounts I ,f!f !s ____ eP _l -an ? 112 \ ,ate medium base 3AN05RT In alp o IIf t BI ?— o 'en��I. --? In ''tn I t In .Ise <.I I Iw IT I25 e ' I at 'ltd IS IMe2edlee ,In III III medm oath 135 fr 4620— sIv __ _. __ s..In _.. I•`I2e I I. m =.(rare "II IQ---stiff.sandy.oath L- In —4620 5 Ile I Beduin brae todetaegtwdty Interbedded very $ CV.Yadt w `:ltd SANG wit ecallened clay eeans CIiii .:Its stiff,sky CLAY Ist In l:Io, medium*we Ir LL ':In with valyiig SANDISILI IN I amounts ofSANO -:12e ...ill: 'en '-I1e :.Iso andmeclm a o ? 4600—. I12 _ -_ __.__ .:Iv ___ dance SANQ'8Ri ' In Sataand5. ID 600 ____. `:Ue ' I5IC sdbi CLAY? tIn ' N ' _� ? II0TT ' III,e5gy. =5dY 1 IN. _ I� III 1�5' er5 Weathered 9 Y _` '4 =51S S 4580— 91811£ III' ISe� -�eac I Fresh_. - Very rend he-d and / 4580 saa SILT end hadC AY (Sandstone.SaaslCne,and Devotee) a 1 4560 4560 R 9 21 LEGEND 0 20 40 B-1 Bourg Designation I (Pro 1 SNI—Projected Distance NOTE Vertical Scale el Feel This subsurface profile Is generalized from 'P I ss` 0 50 100 matenah observed In sod borings. bons Lone Tree Wastewater Treatment Plant Standard Penetration Test $ Water Level Observed Blows/Fool L During Drilling '--x _� I I may exist between profile and actual al co conditions. Facilities Improvement Project v =era--Standard Penetration Test Gill,Colorado 141 Dealer Level Measured in Blows/inches Driven Horizontal Scale in Feet II Vertical Exaggeretinn=2.5X GENERALIZED SUBSURFACE Ptezomeler and Date _. Graphic Symbol PROFILE A-A' ' .n Approximate Geologic Contact June 20% 23-1-0'114-001 Bottom of Boring NH ANHON 6 WILSON,INC. s .a.,.-o........„,wm I FIG.3 SHANNON&WILSON,INC. APPENDIX A FIELD EXPLORATIONS r i 23-1-01114-001 SHANNON&WILSON.INC. APPENDIX A TABLE OF CONTENTS LIST OF FIGURES Figure No. A-1 Soil Classification and Log Key(2 pages) A-2 Rock Classification and Log Key A-3 . Log of Boring B-1 (2 pages) A-4 Log of Boring B-2 (2 pages) A-5 Log of Boring B-4(2 pages) A-6 Log of Boring B-5 A-7 Log of Boring B-6 A-8 Log of Boring B-7 (2 pages) A-9 Log of Boring B-8 A-10 Log of Boring B-9 (2 pages) A-11 Log of Boring B-10 (2 pages) zn-i-ou iaooi-ei „na« 23-1-01114-001 A-i "-, Shannon 8 Ilrlson, Inc. (S8140, uses a soil GRAIN SIZE DEFINITION classification system modified from the Unified Soil Classification System(USCS). Elements of DESCRIPTION SIEVE NUMBER ANDIOR SIZE the USCS and other definitions are provided on this and the following page. Soil descriptions FINES <#200(O.OB mm) are based on visual-manual procedures(ASTM SAND' D 2488-93) unless otherwise noted. -Fine #200 to#40(0.08 to 0.4 mm) -Medium #40 to#10(0.4 to 2 mm) S&W CLASSIFICATION -Coarse iY10 to#4(2 to 5 mm) OF SOIL CONSTITUENTS • GRAVEL' • MAJOR constituents -F10Q #4 to 3/4 inch(5 to 19 mm) compose more than 50 -Coarse 3/4 to 3 inches(19 to 76 mm) percent,by weight,of the soil. Major cwlsiluents are capitalized(i.e.,SAND). COBBLES • Minor constituents compose 12 to 50 percent 3 to 12 inches(76 to 305 mm) of the soil and precede the major constituents BOULDERS >12 inches(305 mm) (i.e.,silty SAND). Minor constituents •Unless otherwise noted,sand and gravel,when preceded by"slightly'compose 5 to 12 percent of the soil(i.e.,slightly silty SAND). Presets,range from fine to coarse in grain s'¢e- • Trace constituents compose 0 to 5 percent of the soil(i.e.,slightly silty SAND,trace of RELATIVE DENSITY/CONSISTENCY gravel). COARSE-GRAINED SOILS FINE-GRAINED SOILS N,ST, RELATIVE N,SPT, RELATIVE MOISTURE CONTENT DEFINTnONS BLOWS/FT. DENSITY BLOWS/FT. CONSISTENCY Dry Absence n dot moisture,dusty,dry 0-4 Very loose Under 2 Very soft ch 4-10 Loose 2-4 Soft Moist Damp but no visible water 10-30 Medium dense 4-8 Medium stiff 30-50 Dense 8-15 Stiff Wet Visible free water,from below Over 50 Very dense 15-30 Very stiff water table Over 30 Hard ABBREVIATIONS WELL AND OTHER SYMBOLS ATD At Time of DrillingRE � Elev. Elevation Bent.Cement Grout Y"�•�≥`�' Surface Cement Seal ft feetA Bentonite Grout sphalt or Cap FeOeO Iron Oxide MgO Magnesium Oxide Bentonite Chips re.s,,,,-4 Slough HSA Hollow Stem Auger ID Inside Diameter Silica Sand •�� Bedrock in inches • r._J PVC Screen _ lbs pounds Mon. Monument cover -:.1 Vibrating Wire N Blows for last two 6-inch increments NA Not applicable or not available NP Non plastic OD Outside diameter OVA Organic vapor analyzer PID Photo-ionization detector o ppm parts per million 3 PVC Polyvinyl Chloride Lone Tree Wastewater Treatment Plant SS Split spoon sampler Facilities Improvement Project a. SPT Standard penetration test Gill.Colorado Ii- ."•5, USC Unified soil classification WLI Water level indicator SOIL CLASSIFICATION �.� AND LOG KEY i June 2006 23-1-01114-001 i SHANNON&WILSON,INC. I FIG.A•1 Gedecirsral and Envaonmemal Gmrsutanis Sheet lea = UNIFIEEkSelinSSllic t P0UV I l IMSCP.Sr • v.�Eroi11 AsTM D,Z4 T 9t 48&9$ i ski= MAJOR DIVISIONS GRODPIGRAPHIC TYPICAL r�= u f..: SYMBOL ICA DESCRIPTION •-s 6W t.,� Well-gradedrea Min n% rno fines. Clean Gravels (less than 5% ',e a Gravels fines) GP 0(1° Poory graded gravels,gravel-sand (more than 50% )o Dc mixtures,little or no fines of coarse fraction retained on No.4 sieve) Gravels with GM Silty gravels,gravel-sand-sill mixtures Fines COARSE- (more than 12% GRAINED fines) Clayey gravels,gravel-sand-clay SOILS xxlt (more than 50% retained on No. SW Well ad gravelly 200 sieve) Clean Sands ••• • little or no nests' sands, (less than 5% fines) Sands SP ?' . Poorly orr not sand,gravelly sands, (50%or more of s "Y:'' :. coarse fraction - passes the No. 4 sieve) Sands with n SM ."- sand-silt sands,sand- mixturesFiles ,-_• ': (more than 12% fines) SC / Cl ayey layey sands,sand-clay mixtures Inorganic silts of low to medium ML plasticity,irock flour,sandy silts, gravelly iHsg Inorganic lasticityY sr with sight Silts and Clays Moronic clays of low to madam (liquid limit less CL j plastiiidy,gravely clays.sandy clays, than 50) sity days lean days FINE-GRAINED Organic 01 —- Organic silts and organic silty clays of — — low plasticity(50%or more - — passes the No. Ivor 200 sieve) garlic sits,micaceous or MH dalomacus fine sands or silty soils, elastic vlleo Inorganic Silts and Clays — Mor9Gantic clays or madam to high (liquid it 50 or CH 7- clay dty,sandy fat clay,or gravelly fat Organic OH ///�. Organic clays of medium to high plasticity,organic silts HIGHLY- f/t% - ORGANIC Primarily organic matter,dark in -^^-�-� color,and organic odor PT -2-1-^„---' Peat,humus,swamp soils with high SOILS 9 N-AN organic content(see ASTM D 4427) NOTE: No.4 size=5 mm; No.200 size=0.075 mm c t- 0 3 Lone Tree Wastewater Treatment Plant i NOTES Facilities Improvement Project Gill,Colorado 1. Dual symbols(symbols separated by a hyphen,i.e.,SP-SM,slightly silty fine SAND)are used for soils with between 5%and 12%fines or when the liquid limit and plasticity index values plot in the CL-ML SOIL CLASSIFICATION area of the plasticity chart. AND LOG KEY u2.Borderline symbols(symbols separated by a slash,ie., CL/ML,silty CLAY/clayey SILT;GW/SW,sandy GRAVEIJgravely SAND) June 2006 23-1-01114-001 i indicate that the soil may fall into one of two possible basic groups. SHANNON 2 ANNOE WILSON�&eant, I FIG.A-1 Sheet 2 oft APPROXIMATE APPROXIMATE DESCRIPTION FIELD IDENTIFICATION UNCONFMED UNCONFINED COIAPRESSIVE COMPRESSIVE STRENGTH(MPa) STRENGTH(PM Very Low Strength Crumbles under firm blows with point of <5.0 700 geological hammer,can be peeled by a pocket knife Low Strength Can be peeled by a pocket knife with di5cdly, 5.0-25 700-4,000 sheerer indentations made by firm Now with point at geological hammer Moderate Strength Cannot be scraped or peeled by a pocket knife, 25-50 4,000-7,000 specimen can be fractured with a single blow of geological hammer Medium High Strength Specimen requires more than one blow of 50-100 7,000-15,000 geological hammer to fracture it High Strength Specimen requires many blows of geological 100-250 15,000- 38.000 hammer to fracture i Very High Strength Specimen can only be chipped with geological >250 >36,000 hammer w�eaR.e k.f' MsY+rP``tt r 3 s`ci:`'F:e. TERM DESCRIPTION Fresh No visible signs of rock material weathering:perphaps slight discoloration on major discontinuity surfaces. Slightly Weathered Seght penetration of discoloration away Iran facture.Fractures may contain thin filling. - Moderately Weathered Partial to complete discoloration away from fracture.Rock not friable except for poorly cemented rock.Fractures may contain thick Ming. HigNy Weathered Ai rock Is discolored.Rock is friable except for poorly cemented rock.Corestones may be present Completely Weathered All rock is decomposed andlor disintegrated to soil.The original mass is still largely Intact. DESCRIPTION SPACING(MM) SPACING(FT) Extremely Close Spacing <20 <0.07 Very Close Spacing 20-60 0.07-0.20 Close Spacing 60-200 0.20-0.66 Medium Spacing 200-600 0.66-2.0 Woe Spacing 600-2,000 2.0-6.6 Very Wide Spacing 2,000-6,000 6.6-20 Lone Tree Wastewater Treatment Plant Facilities Improvement Project Gill,Colorado ROCK CLASSIFICATION AND LOG KEY ,�. Reference:Brown,E.T.,ed.,1981,Rock characterization testing and monitoring ISRM suggested methods:New June 2006 23-1-01079-001 York,International Society for Rock Mechanics SHANNON 8 WILSON,INC. C_aaa-i endthkminl.WGl.l.as FIG.A-2 SOIL DESCRIPTION LL o d - r, u. PENETRATION RESISTANCE £ E a. ' $ A Blows per Foot(SPT) m m 2 m 2 3 a ♦ Blows per Foot(non-standard) Surveyed Elevation is 4649.4 Ft. O N O 0 20 40 60 Road Base • 1 0 •� r . . . . . . . . . j . . . . Loose,brown to gray,slightly sandy SILT; moist; (Fill)ML. . . . Medium dense to stiff,light brown to gray, 5'0 IN 5 V • sandy SILT to silty CLAY;moist;scattered . . . . sand seams;MUCL. • - 1 . . 2,4 10 1.--1-• O61 3N 15 • Medium dense to very dense,brown-gray,fine 16'0 gravelly SAND,trace silt;moist to wet; .� 20 - scattered sandy clay seams; SW/SP. • . . . . . • T 25 • • .,••••-• • Q ! _ -medium stiff,light brown to gray,sandy 30 CLAY;moist;CL from 30.6 to 30.9 feet. • 1 . A . _ • T ::• : I Si.. e 45 ___ rc -coarse gravel in sample 9.Heave observed - at 45 feet. vs CONTINUED NEXT SHEET . .• . e LEGEND 0 20 40 60 i- • Sample Not Recovered V Ground Water Level AID O % Fines(<0 omnvn s? H Modified California Sampler • %Water Content I Standard Penetration Test Plastic Limit ♦--j Liquid Limit az Natural Water Content x al 2 Lone Tree Wastewater Treatment Plant "- Facilities Improvements Project NOTE Gill,Colorado T The boring was performed using hollow stem auger drilling methods. 2.The stratification lines represent the approximate boundaries between sod types.and the transition may be gradual. LOG OF BORING B-1 i 3 The discussion in the text of this report is necessary for a proper understanding of the nature of the subsurface materials o 4.Groundwater levet,if indicated above,is Ice the date specified and may vary. June 2006 23-1-01114-001 cr w 5.Peter to KEY for explanation of symbols,codes and definitions. 6.USCS designation is based on visual-manual classification and selected lab testing. SHANNON 8 WILSON INC. FIG. A'3 a GWechnical and Ennrmmentat C°nsWlants Sheet 1 of 2 SOIL DESCRIPTION �- $ •m 9 IL PENETRATION RESISTANCE E n ,_ • Blows per Foot(SPT) gra a m 3 m V Blows per Foot(non-standard) Surveyed Elevation is 4649.4 Ft. O r.0 O 0 20 40 60 :•:• to I . Medium dense to very dense,fine gravelly SAND;SW/SP(cant.) Very dense,brown,silty,fine SAND;wet;no55 cementation;SM. '•• • •• t'= • j bUm a (SANDSTONE: Very low strength,brown, highly weathered.) :> I . . . . • :' I2S 60 I—• /576' Very dense,dark gray,silty,fine SAND;moist; 63.0 . . no cementation;SM. .• '. 65 3= \(SANDSTONE: Very low strength,dark gray, 65 ----7577* .6 fresh.] 1 . BOTTOM OF BORING COMPLETED 5/9/06. 70 • • Note: Samples below 45 feet were obtained . . from an offset boring. - . . . 75 80 85-_ - 90 • • LEGEND 0 20 40 60 • Sample Not Recovered V Ground Water Level ATO O %FInes<p.075rtxn) H Modified California Sampler • %11SI Water__�__ Content , % I Standard Penetration Test Plastic Limit Liquid Limit Natural Water Content Lone Tree Wastewater Treatment Plant Facilities Improvements Project NOTES Gill,Colorado _ 1.The boring was performed using hollow stem auger drilling methods • 2.The stratification Ines represent the approximate boundaries between soil types.and the transition may be gradual. LOG OF BORING B-1 i 1 The discussion in the text of this report is necessary for a proper understanding of the nature of the subsurface materials 4.Groundwater level.if indicated above,is for the dale specified and may vary. June 2006 23-1-01114-001 ¢ 5 Peter to KEY for explanation of symbols codes and definitions. SHANNON $WILSON INC. FIG.A•3 6.USCS designation is based on visual-manual classification and selected lab testing. and a Environmental Cmsiaants Sheet 2 of 2 SOIL DESCRIPTION ii a .03 0 .. u_ PENETRATION RESISTANCE fi E a o m .c • Blows per Foot(SPT) a m ,j m 0 3 V Blows per Foot(non-standard) Surveyed Elevation is 4650.3 FL ❑ w 0 20 40 60 Medium slit/to stiff,brown to gray;sandy,silty :tt. ', /4CLAY to clayey SILT;moist;(Fill)CUML. •;;t 4' ; - - - - - itttt G 5 wit t i . . . . . �� t lr Ot • 0 • 2 t it;:it. i . Loose, brown-gray,silty SAND;moist;SM. 10.0fill j ! 10 � 5 •- O jMedium stiff to stiff,brown-gray,sandy,clayey 15-0 • e ....t. 1%. t5 1• SILT to silty CLAY;moist;MULL. 7 4 • Medium dense to dense,brown-gray,fine 18.o / % ! _ . .> ..- gravelly SAND,trace silt;moist to wet; % % 20 scattered sandy clay seams;SP. 44 •. . o . 25 . . . . . . . • -. __ _ 45 4 e _ • +d CONTINUE.NEXT SHEET - - - - o LEGEND 0 20 40 60 o Sartple Not Recovered I Glezomeler Screen and Sand Filter % Fines(<0.075mm) u H Modified California Sampler ® Bentonite-Cement Grout • 0 %Water Content 3 I Standard Penetration Test 111'a Benlonite Chips/PelletsPlastic Limit f+ j Liquid Limit ® Bentonite Grout Natural Water Content 1 Ground Water Level in Well Lone Tree Wastewater Treatment Plant I' Facilities Improvements Project NOTES Gill,Colorado I The bong was performed using hollow stem auger drilling methods. 2.The stratification fines represent the approximate boundaries between soil types.and rti — ry the transition may be gradual W 3-The discussion in the text ot this report is necessary frx a proper understanding of the LOG OF BORING B-2 LL nature of the subsurface materials. o 4 Groundwater level,it indicated above,is for the date specitetl and may vary. June 2006 23-1-01114-001 wa 5.Refer to KEY for explanation of symbols,codes and definitions. ' 6.USCS designation is based on visual-manual classification and selected lab testing. SHANNON$WILSON INC. FIG. A4 and Enwonmental Consultants Sheet 1of2 LL '5 , ro Lc. PENETRATION RESISTANCE SOIL DESCRIPTION n E m % • .d- A Blows per Foot(SPT) Surveyed Elevation is 4650.3 Ft. o m CO ti 0 3 m Blows per Foot(non-standard) U 20 40 Medium dense to dense,tine gravelly SAND; I 60 SP(cont.) " 14 _ iI I_I___ l Very dense,brown,silty,fine SAND;wet; no 53.0 • ;=r: - cementation;SM. ;. 15.-. 55 - 1 - [SANDSTONE: Very low strength,brown, _ Strew highly weathered.] _ - ,.`�; j . . . _ 60 161 iQ�' • 50/5', %\< i . -''- nhA. Ii<�% 65 _.— 7$/p to �`,, • . .10014 Very dense,dark gray,silty,tine SAND;moist; 68.0 -�-� •'\\,• - no cementation;SM. 40' - - - ]SANDSTONE:Very low strength,dark gray, r 70.6 .,, • ter= L,...—., 70 • 100/7' \fresh.] BOTTOM OF BORING C• OMPLETED 5/12/06. - -75 • 80 _ • 85 • 90 _ ____ 95 — et EL GEND 0 20 40 60 _ o ' Sample Not Recovered EEO Piezometer Screen and Sand Fitter O %FIne5(<0075mm) H Modified California Sampler ® Bentmile-Cement Grout • %Water Content I Standard Penetration Test :,ut Benlanite Chips/PelletsPlastic Limit I--' --4 Liquid Limit z < ® Bentonite Grout Natural Water Content N a 3 Ground Water Level in Well Lone Tree Wastewater Treatment Plant u Facilities Improvements Project 4 NOTES 1.The bprl Gill,Colorado ng was performed using hollow stem auger drilling methods 2.The stratification Ines represent the approximate boundaries between soil 1 es,and .� N the transition maybe gradual Yp i 3.The discussion in the text of this report is necessary for a proper understanding of the LOG OF BORING B-2 C nature of the subsurface materials. 0 4.Groundwater level,if indicated above,is for the date specified and may vary June 2006 23-1-01114-001 a 5 Refer to KEY for explanation of symbols.codes and definitions h 6.15x'5 designation is based on visual-manual classification and selected lab testing. SHANNON S WILSON,INC. FIG. Al Gedahn,raiaq Environmental G°nWanis $hee12o12 SOIL DESCRIPTION it o m v. .. 1L PENETRATION RESISTANCE 5 r E e ° . ♦ Blows per Foot A Blows per Foot(non-standard) Surveyed Elevation is 4648.3 Ft. N CO 3 O 0 20 40 60 Road Base a Ilw 1 Medium stiff,light brown to gray,sandy,silty 1.0 I CLAY to clayey SILT;moist;(Fill?)CUML. - - - . . - 1I 5 Very stiff,light brown to gray,sandy,silty 8'0 i CLAY to clayey SILT;moist;scattered sand 70 I seams;CUML. 21 ( - - . .•- j i aI 15' Medium dense to very dense,brown-gray,fine 18.0 gravelly SAND,trace silt;moist to wet;SP. Y0 • - 25 eI ._s' 30 . . I E , 35 I TV • Slough in sample 78; blow count may not be 40 - -- --- 7a representative. IT - - _ I �f" 45 -- --- -- iCONTINUED NEXT SHEET LEGEND 0 20 40 60 . `o • Sample Not Recovered V Ground Water Level AID r? I Standard Penetration Test 3 Plastic Limit i-+—j Liquid Limit z Natural Water Content x v, Lone Tree Wastewater Treatment Plant O Facilities Improvements Project Gill,Colorado I The boring was performed using hollow stem auger drilling methods. 2.The stratification Ines represent the approximate boundaries between soil types,and he transition may be grackle!. LOG OF BORING B-4 z 3.The discussion in the text of this report is necessary for a proper understanding of the CZ nature of the subsurface materials p 4 Groundwater level,if indicated above.is for the date specified and may vary. June 2006 23-1-01114-001 a 5.Refer to KEY for explanation of symbols.codes and definitions. 6.USCS designation is based m visual-manual classification and selected lab testing. SHANNON&WILSON INC. FIG.A-5 c Goiechncat and Environmental Cation Sheet 1 d 2 SOIL DESCRIPTION LL — a v LL PENETRATION RESISTANCE t n °-' -.F: A Blows per Foot(SPT) a T l? 3n V Blows per Foot(non-standard) Surveyed Elevation is 4648.3 Ft. O 0 0 20 40 60 Medium dense to very dense,fine gravelly al , I 1. SAND;SP(cont.) I 53.0 i i Very dense,brown,silty,fine SAND;wet no I cementatlon;SM. 55 - — [SANDSTONE: Very low strength,brown, ': t° - 100/Ta highly weathered.] _ I T 60 • Hard,dark gray,silty CLAY;moist;CH. i 61 0 5jyy " - - 90/127a;At ICLAYSTONE: Very low strength,dark gray, 61.5 - resh.] • BOTTOM OF BORING 65 • -- -- COMPLETED 5/11706. i 70 - — — 75 I • ,--. 80 85 - c y 95 i • 4. LEGEND 0 20 40 60 _ c • Sample Not Recovered $ Ground Water Level ATD Standard Penetration Test 3 Plastic Limit F--t/--- Liquid Limit z Natural Water Content a z v,a Lone Tree Wastewater Treatment Plant u Facilities Improvements Project S NOTES Gill,Colorado 1.The boring was performed using hollow stem auger drilling methods.rir 2.The stratification fines represent the approximate boundaries between soil types,and the transition may be gradual. LOG OF BORING B-4 i 3.The discussion in the text of this report is necessary for a proper understanding of the it nature of the subsurface materials. 0 A Groundwater level,if indicated above,is for the date specified and may vary. June 2006 23-1-01114-001 w 5.Refer to KEY lot explanation of symbols,codes and definitions. w 8.USCS designation is based on visual-manual classification and selected tab testing SHANNON 8 WILSON INC. FIG.A-5 i Geotecrnit i and Environ mental W Consultants Sheet 2 of 2 SOIL DESCRIPTION LL 'o o LL PENETRATION RESISTANCE £ E a o m fi •♦ Blows per Foot(SPT) >, 3 a ♦ Blows per Foot(non-standard) Surveyed Elevation Is 4649.3 Ft. p W W O Road Base — 1.0 emr I - 0 20 40 60 Stiff,brown,silty CLAY,trace sand;moist; (Fill?)CH. tN s . . . • . . . j � I YN 10 -I • o96 13.0 Medium dense,brown SAND,trace silt and : ;; • gravel; moist;SP. N 15_a I ::. 3 Medium dense to dense,brown-gray,fine 18.0 gravelly SAND,trace silt;moist;SP. T 20 • i SI 25 • • g 30 • BOTTOM OF BORING 31.6 6 a _ j • s • COMPLETED ON 5/10/06 - - 1 - s o . . . . . . . . . . • 40 -- • 45 0 20 40 60 LEGEND • Sample Nol Recovered V Ground Water Level ATD O % Fteesjco 075mm) u N Modified California Sampler • %Water Content I Standard Penetration Test Plastic Limit I---�---{ Liquid Limit Natural Water Content ut Lone Tree Wastewater Treatment Plant Facilities Improvements Project NOTES Gill,Colorado /.The boring was performed using solid flight auger drilling methods. • - 2.The Stratification lines represent the approximate boundaries between soil types,and rti the transit on may be gradual. LOG OF BORING B-5 r a The discussion in the text of this report is necessary for a proper understanding of the LL nature of the subsurface materials oa.Groundwater level,if indicated above,is for the date specified and may vary. June 2006 23-1-01114-001 o: 5.Refer to KEY for explanation of symbol,codes and definitions. 6.USCS designation is based on visual-manual classification and selected lab testing. SHANNON 8 WILSON INC. FIG.A•6 Geotecnr:cal and Enwonmenlai Cmiullarus SOIL DESCRIPTION �- o y v LL PENETRATION RESISTANCE t, a a m £ • Blows per Foot(SPT) m E7 3 m ♦ Blows per Foot(non-standard) Surveyed Elevation is 4647.8 Ft. 0 N 0 20 40 60 Road Base — i0 ° Soft to medium stiff,light brown to gray,silty CLAY;moist;scattered sand seams;(Fill?) - . . . . . . . . . . CH. . . . . . I . . 5 . 2 Medium dense,brown,slightly silty SAND; 9.0 _ 10 0 moist;scattered clayey sand seams;SP-SM. Medium dense to very stiff,brown-gray,sandy 13'53 SILT to clayey SILT;moist;ML. 5 15 • 6 -• ! . . . _ . . . . . Medium dense,brown-gray,fine gravelly 18'0 i . . SAND,trace silt;moist to wet;SP. 20 • I 25 ' 30 BOTTOM OF BORING 32.0 COMPLETED ON 5/11/06. 8 • 35 -- 40 .-. ---- $ 45 . . . 'I rc • LEGEND 0 20 40 60 c Sample Not Recovered 4 Ground Water Level ATD O %Flnes(ro.075mm) 0 I Standard Penetration Test • %Water Content Plastic Limit Natural Water Content p Limit Lone Tree Wastewater Treatment Plant O Facilities Improvements Project N TES Gill,Colorado 1.The bonng hes performed using hollow stem auger driting methods 2 2.The stratification knes represent the approximate boundaries between soil types.and the transit on may be gradual. LOG OF BORING B-6 'L 3.The dispersion in the text of this report is necessary for a z po proper understanding of the nature of the subsurface materials 0 4.Groundwater level.if indicated above,is for the date specified and may vary. June 2006 23-1-01114-001 w 5.Refer to HEY for explanation of symbols.codes and definitions. /� w 6.USCS designation is based on visual-manual classification and selected lab testing. SHH 1 and 0&WILSON�ns;d!NC FIG.A-7 /0-- SOIL DESCRIPTION LE- B a, c `m tl PENETRATION RESISTANCE • �'a E E o A Blows per Foot(SPT) Qm to in 3 •♦ Blows per Foot(non-standard) Surveyed Elevation is 4648.2 Ft o Soft,light brown to gray,silty CLAY;moist; 0 20 40 60 scattered sand seams;(Fill)CH. - j 5 . • I Loose to dense,brown,clean to silty SAND, 7.0 _ - • . trace fine gravel;moist;scattered sandy clay _ � . . - - seams;SP/SM. - - 10 • Medium dense to dense,brown-gray,fine 15.0 . N 15 • gravelly SAND,trace silt;moist to wet; r • I . scattered sandy clay seams;SP. .. I - 20 25 Y i 30 m� �`- . . . . . 0 ,°. . 121 40 - -- - i . -stiff,light brown to gray,silty CLAY; moist;CL 45 —. _ from 45 to 46 feet. taT - - •. cN CONTINUED NEXT SHEET �:�.:,: S LEGEND 0 20 40 60 o Sample Not Recovered Y Ground Water Level ATD LI N Modified Caflornia Sampler 3 I Standard Penetration Test Plastic Limit )—♦� Liquid Limit z 4 Natural Water Content �, Lone Tree Wastewater Treatment Plant Facilities Improvements Project NOTES 7. 1.The boring was performed using hollow stem auger drifting methods. Gill,Colorado 3. 2.The stratification fares represent the approximate boundaries between soil types.and -, the transition may be gradual. z 3.The discussion in the text ofthis report is necessary for a proper understanding of the LOG OF BORING B-7 nature of the subsurface materials c 4.Groundwater level,if indicated above.is to,the date specified and may vary June 2006 n 5.Refer to KEY for explanation of symbols,codes and definitions- 23-1-01114-001 6.uscs designation is based on visual-manual classification and selected lab testing SHANNON&WILSON INC. FIG.A-8 S Gm m re tecnnral and E 'vowniat ConsimaNs I Sheet 1 of 2 SOIL DESCRIPTION LL $ €1)i -o ti PENETRATION RESISTANCE - n Dry - ♦ Blows per Foot(SPT) d rn m 2 d V Blows per Foot(non-standard) Surveyed Elevation is 4648.2 Ft. 0 0 0 20 40 60 Medium dense to dense,fine gravelly SAND; to 1 ! SP(cont.) _ . . Very dense,brown,silty,fine SAND;wet;no 53.0 '� cementation;SM. 15 55 I v (SANDSTONE: Very low strength, brown, 's . • . . .ti 's highly weathered. - - : ti -wpm' 50 „ „♦ le I .• 1 l ;'♦ Very dense,dark gray,silty,fine SAND;moist; 65.0 19,04 65 F•- r---X5/6"7 no cementation;SM. [SANDSTONE: Very low strength, dark gray, 68.0 " -. \fresh.] r / . . Hard,dark gray CLAY;moist; CH. 70.5 CLL...... 70 It 75/5-wv Af [CLAYSTONE: Very low strength,dark gray, resh.) BOTTOM OF BORING _ . . COMPLETED ON 5/12/06. 75 80 85 _.—._.____ • • • 90 • 99 Ix a . . . LEGEND 0 20 40 60 o • Semple Not Recovered V Ground Water Level ATD to H Modified California Sampler g I Standard Penetration Test Plastic Limit I-411--I Liquid Limit Natural Water Content 4 to g Lone Tree Wastewater Treatment Plant Facilities Improvements Project NOTES Gill,Colorado 1.The boring was performed using hollow stem auger drilling methods. q 2 The stratification Ines represent the approximate boundaries between sod types,and the transition may be gradual. LOG OF BORING B-7 i 3.The discussion in the text of this report is necessary for a proper understanding of the nature of the subsurface materials. p 4 Groundwater level,if indicated above,is for the date specified and may vary. June 2006 23-1-01114-001 cc Ls' 5.Refer to KEY for explanation of symbols,codes and definitions. l 6.Dtesting. SCS designation is based on visual-manual classification and selected lab SHANNON 8.WILSON, INC. FIG.A-8 4 GeotecMical and Environmental Consultants Sheet 2 ol 2 a a a SOIL DESCRIPTION I 7, m 1L PENETRATION RESISTANCE $ E a o' m fi • Blows per Foot(SPT) o to m ♦ Blows per Foot(non-standard) Surveyed Elevation is 4648.2 FL 0 0 20 40 60 Road Base and asphalt pieces. 1 0 •v.1 •.? Very soft to medium stiff,light brown to gray, tit sandy,silty CLAY;moist; (Fill)CH. '. t 5 1 �t • 1A . G . . • Loose to medium dense,brown SAND,trace 10'0 10 Sill;moist;SP. - 2t ' • Medium dense to stiff,brown,interlayered silty 13.4 {1 z1 SAND to sandy SILT to silty CLAY,trace f B 15 I—I 'f . gravel;moist SM/MUCL. 16.0 • I Medium dense to dense,brown-gray,fine �_ gravelly SAND,trace silt;moist to wet; `"' scattered sandy clay seams;SP- 20 s - �-1:111;1•111 I _ 25 B • $ 30 v _ is . . I-stiff,light brown to gray, sandy,silty CLAY; a = moist;CL from 35.8 to 35.9 feet. in ,,Q" �' BOTTOM OF BORING 44.0 -- i i _ . _ . . COMPLETED ON 5/11/06. 45 — C a LEGEND 0 20 40 60 o Sample Not Recovered WI Piexorneter Screen and Sand Filter '? I Standard Penetration Test ® Bentonite-Cement Grout 2 t:•'? Bentonite Chips/PetI-41-1ets Plastic Limit II Liquid Limit i ® Bentonite Grout Natural Water Content in Ground Water Level in Wet Lone Tree Wastewater Treatment Plant o Facilities Improvements Project NOTES Gill,Colorado 1. The boring was performed using hotow stem auger driting methodsZii — 2.The stratification lines represent the approximate boundaries between soil types.and the w transition may be gradual. LOG OF BORING B-S z 3.The discussion in the text of this report is necessary for a proper understanding d the u nature of the subsurface materials. 0 4.Groundwater level,if indicated above,is for the date specified and may vary. June 2006 23-1-01114-001 w 5.Refer to KEY for explanation of sy,urns,codes and definitions. a 6.USES designation is based on visual-menus classification and selected tab testing. SHANNON nv WILSON,INC- FIG. A-9 M Geotechnical and Erwrmme.yy m CouezMs r SOIL DESCRIPTION LL s N a it PENETRATION RESISTANCE t a a . 11 < ♦ Blows per Foot(SPT) m E, E E 3 d ♦ Blows per Foot(non-standard) Surveyed Elevation is 4646.2 Ft. N m 0 20 40 60 Medium dense to dense,brown-gray,fine _ gravelly SAND,trace silt; moist to wet;loose . . . . . . . . . . above 6 feet;SP. . . above - - . . .r 1NT 5, ..tA p I . :Cc': 10 21 • i . . . . . . . . . . . 15 ; 20 • I ::.: 25 V I 30 - • - 5 1 • T 35 ___. ____ -_____-_!_-__-__ 1 • ______I • -___ _- ce aI 7f" CONTINUED NEXT SHEET 0 20 40 60 LEGEND O %Fines(<o ot5mm) i- • Sample Not Recovered ¢ Ground Waler Level ATD o 15 N Modified California Sampler • %Water Content § I Standard Penetration Test Plastic Limit 1---0--I LiquidLimit i Natural Water Content x aLone Tree Wastewater Treatment Plant c? Facilities Improvements Project -. 8 NOTES Gill,Colorado 1.The boring was performed using hollow stem auger drafing methods '4; 2.The stratification lines represent the approximate boundaries between soil types,and ,^„ the transition may be gradual i i 3.The discussion in the text of this report is necessary for a proper understanding of the LOG OF BORING B-9 • nature of the subsurface materials. O 4.Groundwater level,if indicated above,is for the date specified and may vary. June 2006 23-1-01114-001 cc w 5.Refer to KEY for explanation of symbols.codes and definitions. A-10 a s.USES designation is based on visual-manual classification and selected lab testing. SHANNON&WILSON INC. FIG,M-1 Ge°lec nical anti Environmental Cariuttsms Sheet 1 0 2 s SOIL DESCRIPTION t+- m ti PENETRATION RESISTANCE _ E c = m A Blows per Foot(SPT) o o- °3 . ♦ Blows per Foot(non-standard) Surveyed Elevation is 4646.2 Ft. 0 0 20 40 60 Medium dense to dense,fine gravelly SAND; ,o .,SP(coot.) 1 . . -- 52_0 . Dense to very dense, brown,silly,fine SAND . to fine sandy SILT;wet; no cementation; SM/ML. . • rratry 55 • . . . . . .b' L [SANDSTONE/SILTSTONE: Very low '� strength,brown,highly weathered] ,2N . . . 60 �) I Very dense,dark gray,silty,fine SAND to fine 65.0 • ' 65 j sandy SILT;moist;no cementation;SM/ML. 13N - • - - j 150it2'♦ [SANDSTONE/SILTSTONE: Very low 68.0 \strength,dark gray,fresh] / j 1 Hard,dark gray CLAY;moist;CH. r 10.5 A 14►1 70 •. 59/6"v [CLAYSTONE: Very low strength,dark gray. / rear] / BOTTOM OF BORING COMPLETED ON 5/10/06. 75 t t 80 _ . . . 85-- _____ _- . 00 i e LEGEND 0 20 40 60 _ Sample root Recovered o Hj Ground Water Level MD O %Fines(<0.075mm) Modified CaliforniaCatfornia sampler • %Water Content 3 I Standard Penetration Test Plastic Limit z Natural Water Cho Liquid e Limit in u Lone Tree Wastewater Treatment Plant Facilities Improvements Project NOTES Gill,Colorado I The boring was performed using hollow stem auger drilling methods. — 2 The stratification lines represent the approximate boundaries between soil types,and iiii o the disc dnmaybegaduat LOG OF BORING B-9 w 3.The discussion in the text of this report is necessary for a proper understanding of the I .. nature of the subsurface materials. 4.Groundwater level.it indicated above,is tor the date specified and may vary. June 2006 23-1-01114-001 a 5.Refer to KEY for explanation of symbols,codes and definitions. in 6.USCS designation is based on visual-manual classification and selected lab testing. SHANNON&WILSON INC. FIG.A-10 Geoiechrica and Enwwxnental Consultants Sheet 2 of 2 SOIL DESCRIPTION Li o m ' u_ PENETRATION RESISTANCE n z S _e ♦ Blows per Foot(SPT) d m S 3 m ♦ Blows per Foot(non-standard) Surveyed Elevation is 4648.1 Ft. 0 to CO 0 0 20 40 60 Stiff,brown-gray,silty CLAY;moist;(Fill). I . . CUCH. II _ . 1N 5 • I - Medium dense,brown SAND,trace gravel; 8.0 .. . . . . . . . . • ._ . . . . . . . . . moist;scattered clay layers;SP. ! :. 2N to • • 'y i Stiff,brown-gray,sandy,silty CLAY;moist; 13.0 CL. 15 3N • Loose to dense,brown-gray,fine gravelly • ta.o SAND,trace silt;moist to wet;scattered sandy T 20- clay seams;SP. 41 b 25 • s • I 61 ; 30 a a 3 I . . -medium stiff,right brown to gray,sandy T� 35 •- 1--••-- r _�e5 CLAY;moist CL from 35 to 35.5 feet. : ! - - - -with coarse gravel below 35.5 feet. - . Stiff,light brown to gray,sandy,silty CLAY; 43.0yj� - - - _ , _ moist;CL. 45 o: a/ . I • I p61 . ae.o ././. air CONTINUED NEJQ SHEET 2 LEGEND 0 20 40 60 _ c • Sample Not Recovered X Ground Water Level ATD O % Fine5(<0075mm) J H Modified California Sampler • %Water Content Plastic Limit g I Standard Penetration Test —•---I Liquid Limit sNatural Water Content N EL Lone Tree Wastewater Treatment Plant iflj Facilities Improvements Project NOTES Gill,Colorado 1.The boring was performed using hollow stem auger Ailing methods. Ail 2.The stratification lines represent the approximate boundaries between soil types,and seri it the transition may be gradual. LOG OF BORING B-10 i 3 The discussion in the text of this report is necessary for a proper understanding of the nature of the subsurface materials 0 4.Groundwater level.if indicated above.is b the date specified and may vary. June 2006 23-1-01114-001 cc w 5.Refer to KEY for explanation of symMlc,codes and definitions. t e.USCS designation is based on visual.manualSHANNON$WILSON FIG.A•1l classification and selected lab resting. GemANN &VVI my eon,INC.IN s Sheet t oft SOIL DESCRIPTION u= m v it: PENETRATION RESISTANCE • rr.- E n . m ♦ Blows per Foot(SPT) CD m e m ♦ Blows per Foot(non-standard) Surveyed Elevation is 4648.1 Ft. O y `n O O 0 20 40 60 Medium dense,brown-gray,fine gravelly :.=:..1 . SAND,trace silt;wet;SP. . . . . Very dense,brown,silty,fine SAND;wet;no 53.0 • cementation;SM. = 55 • bulb [SANDSTONE: Very low strength,brown, = j highly weathered.] • - - nS 60 j O . . _ • bob . . . . . . . . . Very dense,dark gray,silty,fine SAND; moist;no cementation;SM. 65 l [SANDSTONE:Very low strength,dark gray, r °'5 — ta= _ . . . . --i---10076 `fresh-) / BOTTOM OF BORING COMPLETED ON 5/9/06. 70 - Note: Samples below 45 feet were obtained from an offset boring. - . . ! - . - - - • • 75 . . . . . I 80 • . . 85 . 95 • • LEGEND 0 20 40 60 r• • Sample Not Recovered SI Ground Water Levet ATo O %FIoe5(<o.6isnicn `; N Modified cahlornia Sampler • %Water Content I Standard Penetration Test Plastic Limit I--- --I Liquid Limit Natural Water Content Lone Tree Wastewater Treatment Plant Facilities Improvements Project -. NOTES Gill,Colorado 1.The boring was performed using hollow stem auger drilling methods. 2.The stratification lines represent the approximate boundaries between soil types,and ^ the transition may begadual LOG OF BORING B-10 3 The discussion in the text of this report is necessary for a proper understanding of the nature of the subsurface materials. o4.Groundwater level,if indicated above,is for the date specified and may vary. June 2006 23-1-01114-001 ro 5 Refer to KEY for explanation of symbols,codes and definitions. 6.USCS designation is based on visual-manual classification and selected lab testing. SHANNON&WILSON INC. FIG.{+-11 Gedecesccai am Envi ronmental Consonants Sheet 2 of 2 SHANNON&WILSON.INC. APPENDIX B LABORATORY TEST RESULTS 23-1-01114-001 SHANNON&WILSON.INC. APPENDIX B TABLE OF CONTENTS • LIST OF TABLES Table No. B-1 Summary of Laboratory Test Results by Boring(3 pages) LIST OF FIGURES Figure No. B-1 Grain Size Distribution Report for Borings B-I, B-2, B-5, B-6, and B-9 B-2 Grain Size Distribution Report for Boring B-10 B-3 Plasticity Chart for Borings B-1,B-5,B-6, B-8, and B-9 B-4 Plasticity Chart for Boring B-I O 23-i-01114001-RI Draftdoc 23-1-01114-001 B-i TABL_ \I SHANNON WILSON, / SUMMARY OF LABORATORY TEST RESULTS BY BORING • SAMPLE DATA GRAIN-SIZE ANALYSES' ATTERBERG LIMITS STRENGTH CON• BI SWELL/ CORROSION c u E Z l a -y $ Boring Sample Depth v7 . a. C 3 !+` U 8 v _ - (feet) V ,n" !, } '8 + , .1, • _ all co re. •� 79 Top Bottom (%) . (pen (/) (/) (*AI (I) (/.) (6) (Psi • (x) •,{7fa).• :•-•(64O,• ' (ohm-m) (Ptm)'i (Ptw)i, S-1 5.4 6.0 ;42 ) . S.2 1-10.0 10.5 33.4 IIS.9 . .__.. .. .1.290 111 — ----^--- ---- -- , I S-2 I 10.5 1 I.0 CL -..- 22.5 119,7 6i )6 ?I 13 S•3 ' 15.0 16.0 42.7 - 10 157 B-1 S-4 20.0 ' 21.5 Sw 3.6 20 t 76-1 .-._•-.-.. - 8 1 3.0 S� S-S ; 25.0 26.S 3.1 -. --- ---_...... r- - 1 II S-I I I_55.0 55.5 26.1 _-. _.. _..----- .....__ - _ _ ` _•S.12. 60.0 60.5 24.6 ---. ._ _.._... _ .. __ i S•t3 63.0 65.6 27.0 _ S-I 5.0 6.0 191 S.2 6.0 8.0 19.1 CS II -3 .j-IOA 11.0 4.6 I(Y��. _�_ � • S-4 ILO 13_0 '— 9.8 --- —+_— — »- -- S-5 13.0 15.0 �——9.6 _-- 24 56 IMO 16.0 42.1 `, _ - —_ —_— B-2T, 5 7 16.0 18.0 23.3 .�� —.�.... s_...._. —__._.-•_ _ — ---_ Si. 20.0 21.0 1.7 _ S-9 23.0 27.0 1.5 I S•13-1_45.0 47.0 .-... 23.2_.- i - -'- _.._- - r S•15 L 55_0 55.3 20.2 _I -_ _.. _ .»----•-- •- --- S•16 I 60.0 60.9 31.4 ..-- �' -. _-.....-.! 8 5.1 i 65.7 66.0 --_ 30.8 ____ I S-I9 I 70.0 70.6 26.0 --I --^_� 1—S1 ! 5.0 6.5 24.3 L _ __ ) I_sz I lo.o i%5 29:1 4' ) ) ' ' S-3 I 15.0 ( 16.3 —27=7 H-i e.4 S•4�X20.0 I 21.3_ __ 3.3 .».- - _^... -�_ ) S•S _ 2S 0 26.5` 3.6 —— t _ I 5.10 55.0 j 56.5 26.3 —, S•I1 .60.0 , 61.5 21.4 1— _---- --.• ---..--. 11 N0tc1; 'See Appendix A.Figure A-I for definitions. Gravel defined as particles lager than the No.4 sieve size.Sand as panicles bctween he No.4 and No.200 sieve sires,and Fines as particles passing the No.200 sieve. 23-1-01114-001 Lab DataSurrmary.xls Page 1 of 3 23.1-01114-O01 )) SHANNON WILSO. TABLc B-1 SUMMARY OF LABORATORY TEST RESULTS BY BORING SWELL/. SAMPLE DATA GRAIN-SIZE ANALYSES' ATTERBERG LIMITS STRENGTH CORROSION CONSOLIDATION I o .. a I: j ! Depth (: S• L o a f, J 3 V o W • t=•; . ' • ' Bonn Satnplc (feet) C •a tJ y •`� i $ 5 e 8 41 1 Z u t Top Bottom (%) (pcf) (%) (O) (%) (%) (%) (/) • OA. ! (%) • `.(%1 (PO, F . `' 4181 1,':(1) •(IMI)II ) i I SO 5.0 6.0 18.4 107.$ -1,I 1,000 8.0 10 325.0 25.0 I 5-7 10.0 11.0 CH 30.4 106.0 96 60 27 33 7.9 10 69.0 130.0 r53 -....•• • . .- -.. ---- -.-__ __ 7------ -- 15.0 16.0 SP 2.8 1 97 2 _ s-s , _0,0 -..- - -- ' � 21.5 2.1 i :,-}23.0 26.3 2.0 ' 5-e ' 30.0 JI.S 4.8 -- _ _ ..S•1 i 5.0 7.0 34.8 _— ! S•2 7,0 • 9A 310 _ _5 3 10.0 1 .._..__. �.. -_._. — ii.0' 12.0 s.s i 14.0 8.o.., —_ 1 _..__.___.._._ ._.._._.._.. .__. — — — S•S 14.0 16,0 ML 22.1 23 20 J 5.6 I 16.0 i 18.0 S 4.4 :-..S77. .. _. .-. _-.-..._. ..._ ._.. -._-.... . ••--'---..._..._-- --••-••.. .__-._..... .....---- !-'-- --- -7 ! 20.0 + 0- "_2 2.4 ---- S 8 i 25.0 27,0 J.8 = S-1 .1 5.0 6.0 28.9 r- ---- .__.---- -...__.._ _ i 6,0 co 23.2 ; S-3 •1 8.0_1 10.0 _16.1_ 1 - - -_ ...._-^-r--_�••_ _ - �•_- r5-S x-1770 t fill- 5.9 - •• $6 1'15.0 1 16.0 2.6 _... B_7 i.._..5.7 1 16.0 18-0 3.2 I _-.--- ..-- 5-8 i_20.0 • 22-0 7 --' - -f -�_ .-....._.._f_ .....- - -- 5.9 ) 33.0 I 2 � ........_.... .-..--- ..__ . . _...... .. ..._._. .... i_--.-_ _7.0 ---,-=3.. ..._---- --......_..----- -- '-------- •.-_- - .-0 ) S-1J i 55.0 x55.9 29.8 — -- -- _------ 1 i 5•Ib 53.4 I' 55.9 29_0 -� SS 6C7 x61.1- _ 33.4 _ __ ___ __ I y;9 , 65,0 65.s-__ 25.5 —.� —_ __—_ ...-___—_ --- -- ' 5.20 170.O 70.5 14.9 -._ _, I_..__.- _ f Noes 'Ste Appendix A,Figure A•1 fordefiniiions. Gravel defined as partieks brger than the No.4 Steve size,Sand as panicles between the No.4 and No.200 sieve sizes,and Fines as particles passing the No.200 sieve. 23-1-01114-001 Lab Data Summary xis Page 2 of 3 23.1-01114-001 • SHANNON WILSON,' ! TABLL _<1 1 SUMMARY OF LABORATORY TEST RESULTS BY BORING S.%NIPLE DATA £ GRAIN-SIZE ANALYSES' ATfERBERG LIMITS STRENGTH CONSOLIDATION CORROSION a i I ≥ j • 0 - 3 Depth v, Boring Simple (feet) to w y o Jp weo y tj I Top Bottle (%) fpcQ (%) PA) (%) '(%) (%) I (%)_ (pa4 i%) (%) :(Av..• ... :!7!: " 1.O... .:�i iiilvi'�oPo� ) S-1 s.o ;CO 2t1.9 �S IA 7.0 9.0 36.0 ._....._..._-__.. _.__..__.. -�- -- S-2 10.0 12.0 10.6 B B .S-2A 12.0 I 14.0 6.4 - _. _ _ ; S•3 : 14.0 1 16.0 CL 22.1_ t I. _-7tl .. ...HI ._.ii sal—, 16.0 11:0_ J.7 �S _3 wJ.2 I S-6 I 25.0 27.0 2.3 I S-1 5.0 6.0 ICI _ 511ll 1.6 I - 1._A:2-1_5125 S•3 • 15.0 i 16.5 - _•---- .-.. �_ __`_"--- ---• - 7.7 61 <1 4.9_ _•-•... l3_g 4 20.0_ 2t.S --2.1_ _.-�. .- - ---- -----.._.-_.__. _ _.._�- _� __ $-5 I 25.0 26 S SP 2.1 _ 22 -73 5 S-I IA TS 5.3~ 56.3 28.9 - - ---_-..,._ S•12 640 ---61.72-661-..- 21.0 11 T.3 F $6 3l 23 1_ I I r S-IJ 63.5 66.7 24.T -..._ I .�.._ �'s.0 iu.a`7c.s_"' -is.i - - - �_�_:r_ _-_.._._ _. ___..__ �_ _. . —___ I S•I I 5.0 i 6.0 29.9 108.1 _ 1.365 S_.9_ L__S-2 i 10.0.1_11.0 11-0 _____ 5.1 -- _ 5.3 15.0 16.0 2T.6 J _ 13 12.0 517.5 . S•4 i 20.0 21.3 SP 2.4 15 1 82 y3_ ©.10 !-S-S r 25.0 , 26.5 2.6 S-T r 35.0 35.5 CL 24.2 85� SO 19 31 I S•9-..;.45.0 16.0 CL 22.8 61_ J6.,_.- 15._. _..21 - --- --- S•11 X55.0 55.5 27.8_ -_-. I ......_.-._._._- --_.._._...--•- --_ 5-12.._1_60.0 I 60_5-_ SM_ 31.0 ---� _. -._.__.�.._.-- -- 24 _ non-plaslit:__-- — — -- _ 1 S•13 63.0 I 65.5 i 27.9 1 31 Notes; 'See Appendix A.Figure A-I for definitions. s Gravel defined as particles larger than the No.4 sieve size,Sand as particles between die No.4 and No.200 sieve sizes,and Fines as particles passing ilie No.200 sieve. 23-1-01114-001 Lab Data Summary xis Page 3 0(3 23.1-01114-00+ SIEVE ANALYSIS 7.-----. HYDROMETER ANALYSIS �0 SIZE OF MESH OPENING IN INCHES I NO.Of MESH OPENINGS PER INCH,U.S.STANDARD GRAIN SIZE IN MILLIMETERS s_ IS p O z 4 EO p O,p Z uN C N v N ry O O O, O u 100 ,� t iI r 0 0 _ 0 a o 0 N I SC 20 z cc I ♦- H 70 30 0 T- V LU g 60 • 40 m m w ) \\\\\ i N w Z 50 50 Q 1l. O I- i U Z H- U 40 60 W C' U cc a w a 30 I 70 I A 20 80 0 90 R 8 5 8 $ RR D u ors ry - � 0 $ S R ``4 67 RA AR R $100 GRAIN SIZE IN MILLIMETERS COBBLES COARSE I FINE COARSE I MEDIUM I FINE FINES: SILT OR CLAY ) GRAVEL SAND BORING AND DEPTH US.C.S. SAMPLE FINES NAT. LL PL PI SAMPLE NO. (feel) SYMBOL DESCRIPTION % W.C.% % % % Lone Tree Wastewater Treatment Plant Facilities Improvements Project • B-1.5-2 10.8 I CL Sandy.silty CLAY 60.7 22.5 36 21 15 Gill,Colorado IS 9.1,S-4 20.5 4.2 A 8-2.5-5 14.0 SM Silty SAND 24.3 9.6 GRAIN SIZE DISTRIBUTION T • B-5,S-2 10.5 CH Silty CLAY.trace sand 95.8 30.4 5 O 8.5.5-3 15.8 2.4 co O B-6.5-3 10.0 56 June 2006 23-1-01114.001 S. a 8-9.5.1A 6.8 SP Gravelly SAND,trace sill. 4.9 2.3 SHANNON&WILSON.INC. FIG. B-1 a.aw.sM rMte,. aM C. ,a. I SIEVE ANALYSIS HYDROMETER ANALYSIS r g), II SIZE OF MESH OPENING IN INCHES 1 NO.OF MESH OPENINGS PER INCH,U.S.STANDARD GRAIN SIZE IN MILLIMETERS g_ 2 .. gg p zz e • m o A $ $ 8 8 g G. `� S. 21 tl 6 $. 8 8 W 100 , , , , , , , , , , , ,, , , r t t , 0 b ��r��••��r Y On�e��i11�►l� ��1l��Il11ll�ii '° 2 800 !!a!! iiiilaa s 20 a el�i iii auuu !! CD CC 0 CC O 84 al W w!!�!�l�1��l�!!\i!!l�II�! W 30 " 70 20 e0 10 90 I o 1 , , , , ,, , , , , , , , , 100 A A s83 e R 8 ewe CR Ui n 78. . .1 g s o it: Is A A. A A. GRAIN SIZE IN MILLIMETERS ) COBBLES COARSE FINE COARSE MEDIUM FINE AY FINES: SILT OR CL GRAVEL SAND BORING AND DEPTH I U.S.O.S. SAMPLE FINES NAT. LL PL PI SAMPLE NO. (reel) SYMBOL DESCRIPTION x W.C.x x x x Lone Tree Wastewater Treatment Plant Facilities Improvements Project •8-10,5.4 20.0 SP Gravelly SAND,trace di8. 3 4 Gill, Colorado • B-10.5.7 35.3 CL Sandy CLAY 84.7 24.2 50 19 31 ♦ B-10.S-9 45.8 CL Sandy CLAY 61.1 22.8 36 15 21 GRAIN SIZE DISTRIBUTION -n • B-10,5.12 60.3 SM Silty SAND 23.6 31.0 NP NP NP (1) O B-10.5-13 65.3 SM Silly SAND 30.9 27.9 June 2006 23-1.01114-001 CO mw m w,SHANNON&WILSON,INC. FIG.B-2 N Gwevankm am. w.T.,, ca, v 70, ' - - - . i CL CH • , T f. I :. I LEGEND • 8 T ' CL: Low plasticity inorganic . I . ..� . ; { ) days;sandy and silty 'z I. �. T...r. • ! • Gays so r • CH: High plasticty InorganIc c • I clays 1 a . •••' - • • S ' I ML or OL: Inorganic and organic silts x and clayey silts of low liJ o 00 plasticity z i-- i : . r- MH or OH: Inorganic and organic silts I- l . : _; i .i..1..;_.. and clayey silts of high U M ' ; i I. • plasticity V)• JO • I I CL-ML: Silty clays and clayey silts 3 I_ , I ZG 1 -I .i.. • L _i. i . I I U IQ - I • r I CL-ML ML or OL . i..MH or al ii. I • • o ✓ i 0 to 20 30 so So 50 70 SO 90 100 AO 1 LIQUID LIMIT-LL(%) J BORING AND DEPTH I US CS SOtt LL PL r PI NAT. * PASS. Lone Tree Wastewater Treatment Plant SAMPLE NO OW SYMBOL ; CLASSIFICATION % % % W.C.% moo.% •a•1,s•2 10 a CL Sandy,silly CLAY 36 ` 21 15 225 60.7 Facilities Improvements Project Gill,Colorado ■8.5.S-2 10.0 CH Silly CLAY.trace sand 60 27 33 ♦B-6.S-5 15 0 ML Sandy SILT 23 20 3 22.1 PLASTICITY CHART ♦B-8,S•3 15.0 CL Silly CLAY 30 19 11 22.0 11 O S-9.5-12 60.3 ML Sandy SILT 31 23 8 21.0 56.2 • 7 June 2006 23.1-01114-001 A SHANNON&WILSON,INC. FIG.B•3 Gool.au14MM{. ..,...M11.1 Cy..Il.t° ) ) ) 1. i 10 - I• I _ N LEGEND • 60 I I. .. -• I. H I CL: Low plasticity Inorganic ..- . -.I I i _..i 4.1-. days;sandy and silty 1 _i.. __ I- -.-: days f so • ! I I ;.-" I I CH: High plasticity inorganic o a,° _! ,. ; .. . . days ti ii a - - I I I - ML or OL: Inorganic and organic silts a x !... - - _._.,... and clayey silts of low °' ) uj 40 plasticity Y - "- MH or OH: Inorganic and organic silts 1 . _. and clayey silts of high u ..., ..._ • ' plasticity r- • g 30 CL-ML: Silty clays and clayey silts a 20 n ; 10 CL-NIL MLarOL MHcrOH I i ii I .. ; o / .. 0 10 20 30 40 50 60 70 80 90 100 110 LIQUID LIMIT-LL(%) ) BORING AND DEPTH D.S.C.5. SOIL LL Pl. PI NAT. Pass. Lone Tree Wastewater Treatment Plant SAMPLE N0. (lee) SYMBOL CLASSIFICATION % % % W.C.% 0200.% Facilities Improvements Project •B-1O.S-I 35.3 CL Sandy CLAY 50 19 31 24.2 84.7 Gill,Colorado ■0.10,S-9 45.8 CL Sandy CLAY 38 15 21 22.8 61.1 8-10.S-12 60.3 SM Silly SAND NP NP NP 31.0 23.6 PLASTICITY CHART T 0 June 2006 23-1-01114.001 Ca SHANNON&WILSON,INC. IS ,,,I.wrl lad o,,.„,.,„„C,e.e„nt. FIG. B-4 SHANNON&WILSON.INC. APPENDIX C IMPORTANT INFORMATION ABOUT YOUR GEOTECHNICAL REPORT 23-1-01114-001 • I II SHANNON & WILSON, INC.Geotechnical and Environmental Consultants Attachment to and part of Report 23-i-01114-001 Date: June 2006 To: Caner Burgess Denver,Colorado IMPORTANT INFORMATION ABOUT YOUR GEOTECHNICAL/ENVIRONMENTAL REPORT CONSULTING SERVICES ARE PERFORMED FOR SPECIFIC PURPOSES AND FOR SPECIFIC CLIENTS. Consultants prepare reports to meet the specific needs of specific individuals. A report prepared for a civil engineer may not be adequate for a construction contractor or even another civil engineer. Unless indicated otherwise,your consultant prepared your report expressly for you and expressly for the purposes you indicated. No one other than you should apply this report for its intended purpose without first conferring with the consultant. No party should apply this report for any purpose other than that originally contemplated without first conferring with the consultant. THE CONSULTANT'S REPORT IS BASED ON PROJECT-SPECIFIC FACTORS. A geotechnical/environrnental report is based on a subsurface exploration plan designed to consider a unique set of project-specific factors. Depending on the project, these may include: the general nature of the structure and property involved; its size and configuration;its historical use and practice;the location of the structure on the site and its orientation;other improvements such as access roads,parking lots, and underground utilities;and the additional risk created by scope-of-service limitations imposed by the client. To help avoid costly emblems,ask the consultant to evaluate how any factors that change subsequent to the date of the report may affect the reconarmcndations. ess your consultant indicates otherwise,your report should not be used: (1)when the nature of the proposed project is changed(for example, if an office building will be erected instead of a parking garage, or if a refrigerated warehouse will be built instead of an unrefrigerated one,or chemicals are discovered on or near the site);(2)when the size,elevation,or configuration of the proposed project is altered; (3) when the location or orientation of the proposed project is modified; (4)when there is a change of ownership; or(5) for application to an adjacent site. Consultants cannot accept responsibility for problems that may occur if they are not consulted after factors which were considered in the development of the report have changed. SUBSURFACE CONDITIONS CAN CHANGE. • Subsurface conditions may be affected as a result of natural processes or human activity. Because a geotechnical/environmental report is based on conditions that existed at the time of subsurface exploration, construction decisions should not be based on a report whose adequacy may have been affected by time. Ask the consultant to advise if additional tests are desirable before construction starts; for example,groundwater conditions commonly vary seasonally. Construction operations at or adjacent to the site and natural events such as floods,earthquakes,or groundwater fluctuations may also affect subsurface conditions and,thus,the continuing adequacy of a geotechnical/environmental report. The consultant should be kept apprised of any such events,and should be consulted to determine if additional tests are necessary. MOST RECOMMENDATIONS ARE PROFESSIONAL JUDGMENTS. Site exploration and testing identifies actual surface and subsurface conditions only at those points where samples are taken. The data were extrapolated by your consultant,who then applied judgment to render an opinion about overall subsurface conditions. The actual interface between materials may be far more gradual or abrupt than your report indicates. Actual conditions in areas not sampled may differ from those predicted in your report. While nothing can be done to prevent such situations,you and your consultant can work together to help reduce their impacts. Retaining your consultant to observe subsurface construction operations can be particularly beneficial in this respect. Page I of2 1/2002 NEPORTS CONCLUSIONS ARE PRELIMINARY. the conclusions contained in your consultant's report are preliminary because they must be based on the assumption that conditions revealed through selective exploratory sampling are indicative of actual conditions throughout a site. Actual subsurface conditions can be discerned only during earthwork;therefore,you should retain your consultant to observe actual conditions and to provide conclusions. Only the consultant who prepared the report is fully familiar with the background information needed to determine whether or not the report's recommendations based on those conclusions are valid and whether or not the contractor is abiding by applicable recommendations. The consultant who developed your report cannot assume responsibility or liability for the adequacy of the report's recommendations if another party is retained to observe construction. THE CONSULTANTS REPORT IS SUBJECT TO MISINTERPRETATION. Costly problems can occur when other design professionals develop their plans based on misinterpretation of a geotechnical/environmental report. To help avoid these problems,the consultant should be retained to work with other project design professionals to explain relevant geotechnical,geological,hydrogeological,and environmental findings,and to review the adequacy of their plans and specifications relative to these issues. BORING LOGS AND/OR MONITORING WELL DATA SHOULD NOT BE SEPARATED FROM THE REPORT. Final boring logs developed by the consultant are based upon interpretation of field logs(assembled by site personnel),field test results,and laboratory and/or office evaluation of field samples and data. Only final boring logs and data are customarily included in geotechnical/environmental reports. These final logs should not,under any circumstances,be redrawn for inclusion in architectural or other design drawings,because drafters may commit errors or omissions in the transfer process. To reduce the likelihood of boring log or monitoring well misinterpretation, contractors should be given ready access to the complete geotechnical engineering/environmental report prepared or authorized for their use. If access is provided only to the report prepared for you,you should advise contractors of the report's limitations,assuming that a contractor was not one of the specific persons for whom the .report was prepared,and that developing construction cost estimates was not one of the specific purposes for which it was prepared. While mtractor may gain important knowledge from a report prepared for another party,the contractor should discuss the report with your nsultant and perform the additional or alternative work believed necessary to obtain the data specifically appropriate for construction cost estimating purposes. Some clients hold the mistaken impression that simply disclaiming responsibility for the accuracy of subsurface information always insulates them from attendant liability. Providing the best available information to contractors helps prevent costly construction problems and the adversarial attitudes that aggravate them to a disproportionate scale. READ RESPONSIBILITY CLAUSES CLOSELY. Because geotechnical/environmental engineering is based extensively on judgment and opinion, it is far less exact than other design disciplines_This situation has resulted in wholly unwarranted claims being lodged against consultants. To help prevent this problem, consultants have developed a number of clauses for use in their contracts,reports and other documents. These responsibility clauses are not exculpatory clauses designed to transfer the consultant's liabilities to other parties;rather,they are definitive clauses that identify where the consultant's responsibilities begin and end. Their use helps all parties involved recognize their individual responsibilities and take appropriate action. Some of these definitive clauses are likely to appear in your report,and you are encouraged to read them closely. Your consultant will be pleased to give full and frank answers to your questions. The preceding paragraphs are based on information provided by the ASFE/Association of Engineering Firms Practicing in the Geosciences,Silver Spring,Maryland Page 2 of 2 1/2002 Hello