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HomeMy WebLinkAboutGATEWAY APARTMENTS - PDP230001 - SUBMITTAL DOCUMENTS - ROUND 1 - GEOTECHNICAL (SOILS) REPORT CTL|Thompson, Inc. Denver, Fort Collins, Colorado Springs, Glenwood Springs, Pueblo, Summit County – Colorado Cheyenne, Wyoming and Bozeman, Montana Gateway at Prospect Interstate 25 and Prospect Road Fort Collins, Colorado Prepared for: Rockefeller Acquisitions LLC 1401 Lawrence Street, Suite 1600 Denver, Colorado 80202 Attention: Dave Klebba Project No. FC10412-115 November 2, 2022 PRELIMINARY GEOTECHNICAL INVESTIGATION Table of Contents i Scope ............................................................................................................................................. 1 Summary Of Conclusions ............................................................................................................. 1 Site Description ............................................................................................................................. 2 Proposed Development ................................................................................................................. 2 Geologic Hazards .......................................................................................................................... 2 Shallow Groundwater ................................................................................................................ 3 Soft Soils .................................................................................................................................... 3 Seismicity ................................................................................................................................... 4 Radioactivity ............................................................................................................................... 4 Field And Laboratory Investigations .............................................................................................. 5 Subsurface Conditions .................................................................................................................. 5 Development Recommendations .................................................................................................. 6 Dewatering and Stabilization ..................................................................................................... 6 Site Grading ............................................................................................................................... 8 Slopes ........................................................................................................................................ 8 Utility Construction ..................................................................................................................... 9 Preliminary Pavement Recommendations .................................................................................. 10 Preliminary Recommendations for Structures ............................................................................ 10 Foundations ............................................................................................................................. 11 Floor Systems and Slab -on-Grade Construction .................................................................... 11 Below-Grade Construction ...................................................................................................... 11 Surface Drainage ..................................................................................................................... 11 General Design Considerations .............................................................................................. 12 Recommended Future Investigations ......................................................................................... 12 Limitations ................................................................................................................................... 13 FIGURE 1 – LOCATIONS OF EXPLORATORY BORINGS FIGURES 2 AND 3 – SUMMARY LOGS OF EXPLORATORY BORINGS FIGURES 4 THROUGH 6 – SEWER UNDERDRAIN DETAILS APPENDIX A – LABORATORY TEST RESULTS APPENDIX B – GUIDELINE SITE GRADING SPECIFICATIONS ROCKEFELLER ACQUISITIONS LLC GATEWAY AT PROSPPECT CTL|T PROJECT NO. FC10412-115 Scope This report presents the results of our Preliminary Geotechnical Investigation. The purpose of our investigation was to identify geologic hazards that may exist at the site and to evaluate the subsurface conditions to assist in planning and budgeting for the proposed development. The report includes descriptions of site geology, our analysis of the impact of geologic conditions on site development, a description of subsoil, bedrock and groundwater conditions found in our exploratory borings, and discussions of site development as influenced by geotechnical considerations. The scope was described in our Service Agreement (CTL |T Proposal No. FC-22-0446) dated September 29, 2022. This report was prepared based upon our understanding of the develop ment plans. The recommendations are considered preliminary , and can be used as guidelines for further planning of development and design of grading. We should review final development and grading plans to determine if additional investigation is merited, or if we need to revise our recommendations. Additional investigations will be required to design building foundations and pavements. A summary of our findings and recommendations is presented below. More detailed discussions of the data, analysis, and recommendations are presented in the report. Summary Of Conclusions 1. The primary geologic hazard at this site is the presence of shallow groundwater. Other geologic hazards include soft soils , and regional issues of radioactiv e gas and seismicity. No geologic or geotechnical conditions were identified which would preclude development of this site. 2. The subsurface conditions encountered in our borings were variable acro ss the site. In general, the soils encountered in our borings consisted of 5 to 12 feet of sandy clay over clayey to gravelly sand and sandy gravel . Claystone bedrock was encountered in seven borings at 16 to 24 feet to the maximum depths explored. Samples of the soils tested exhibited 2.5 percent swell or less. 3. Groundwater was encountered during drilling at depths ranging from 6 to 14 feet below the existing ground surface. When measured several days later, groundwater was encountered at depths of 5 to 8½ feet in all of the borings. We recommend a minimum 3-foot separa tion (preferably 5 feet) between foundations and slabs , and groundwater. This may limit basement potential for much of the site unless groundwater mitigation efforts are made. Groundwater will likely be encountered in deep utility excavations; dewatering will be necessary. Further monitoring of groundwater levels is recommended. ROCKEFELLER ACQUISITIONS LLC GATEWAY AT PROSPPECT CTL|T PROJECT NO. FC10412-115 4. Soils encountered will likely provide fair to good subgrade support for pavements according to AASHTO criteria. Soft soils were encountered in several borings; stabilization will need to be considered in areas of soft soil. Mitigation for swell is likely not necessary. Preliminary paveme nt thickness recommendations are provided in this report. 5. Overall surface drainage should be designed to provide rapid run -off of surface water away from the proposed residences. Water should not be allowed to pond near the crest of slopes, on or adjacent to pavements, or adjacent to structures. All permanent slopes should be re -vegetated to reduce erosion. 6. Further investigations are required to ma ke design recommendations for foundations, floors, and pavements. Site Description The property is located north of Prospect Road and west of the Interstate 25 Frontage Road in Fort Collins, Colorado. The site consisted of agricultural land with residential housing adjacent to the majority of the property. The site sloped slightly downward to the south and east. Irrigation ditches were located to the north, east , and southeast. These irrigation ditches were unlined and had approximately 1 to 2 feet o f water present during our field activities. A swale was present on the west side of the site with occasional areas of standing water. Residential properties were located to the west and northwest. Light industrial properties were present to the north a nd northeast. Groundcover consisted of grasses and corn stalks. Proposed Development We understand the 12-acre parcel is planned for a multi-family residential development. Preliminary plans indicate ten structures are planned. Roadways are planned to the west, north, and northeast portion of the site. Interior access roads and parking areas are also planned. Geologic Hazards Our investigation identified geologic and geotechnical hazards that must be considered during the planning and development phases of this project. None of the hazards identified will preclude development of the property. Geologic hazards at the site include shallow groundwater, soft soils, and regional issues of seismicity and radioactivity. The hazards require mitigation which ROCKEFELLER ACQUISITIONS LLC GATEWAY AT PROSPPECT CTL|T PROJECT NO. FC10412-115 could include avoidance, non-conflicting use, or engineered design and construction during site development. The following sections discuss each of these geologic hazards and associated development concerns. Mitigation concepts are discussed below and in the DEVELOPMENT RECOMMENDATIONS section of the report. Shallow Groundwater The site has historically been, and is currently, used for agriculture. It is irrigated during the spring, summer, and fall by flood and furrow . Groundwater is likely influenced by irrigation in and around the site, and will fluctuate seasonally. Future groundwater elevation s will need to be re- evaluated after irrigation is ended. Shallow groundwater will likely impact construction under current conditions. Groundwater mitigation efforts can reduce groundwater limitations on construction as discussed below. We recommend a minimum 3 -foot, and preferably 5-foot, separation from foundations and floor slabs to groundwater. Basements should be avoided unless the recommended separation can be mainta ined permanently. Subsurface drainage systems (e.g., underdrains, interceptor drains, etc) are merited in areas to reduce the risk of basement flooding and to control groundwater. Foundation drains should be anticipated around crawl space and basement foundations. Underdrains are a commonly used method to effectively lower and control area groundwater levels, but they will require a gravity outfall and the system could be extensive. Avoidance and adjusting site grades are the most reliable ways to avoid shal low groundwater. Shallow groundwater will likely complicate site development activities such as sewer utility installation. Deep utility installation will require dewatering and soft or muddy soils should be anticipated. Contractors should anticipate sof t soils, wet soils, shallow excavation slopes below groundwater, and dewatering systems. Soft Soils Very soft to soft soils were encountered at various locations and depths, generally near or below groundwater. There is risk of settlement and associated distress to improvements where structures are constructed over soft soils. These soils may compress (settle) under pressure exerted by fill and foundations. Groundwater mitigation may also improve some soft soil areas. Soft soils should be removed and replaced, stabilized, or deep foundations con sidered. ROCKEFELLER ACQUISITIONS LLC GATEWAY AT PROSPPECT CTL|T PROJECT NO. FC10412-115 Seismicity This area, like most of central Colorado, is subject to a low degree of seismic risk. No indications of recent movements of any of the faults in the Larimer County area have been reported in the available geologic literature. As in most areas of recognized low seismicity, the record of the past earthquake activity in Colorado is somewhat incomplete. Based on the subsurface conditions encountered in our borings and ou r understanding of the geology, the site classifies as a Seismic Site Class C (2018 International Building Code). Only minor damage to relatively new, properly designed and built buildings would be expected. Wind loads, not seismic considerations, typically govern dynamic structural design in this area. Radioactivity It is normal in the Front Range of Colorado and nearby eastern plains to measure radon gas in poorly ventilated spaces in contact with soil or bedrock. Rad on 222 gas is considered a health hazard and is one of several radioactive products in the chain of the natural decay of uranium into stable lead. Radioactive nuclides are common in the soils and sedimentary rocks underlying the subject site. Because the se sources exist on most sites, there is potential fo r radon gas accumulation in poorly ventilated spaces. The amount of soil gas that can accumulate is a function of many factors, including the radio -nuclide activity of the soil and bedrock, construction methods and materials, pathways for soil gas and existence of poorly ventilated accumulation areas. It is difficult to predict the concentration of radon gas in finished construction. We recommend testing to evaluate radon levels after construction is completed. If required, typical mitigation methods for residential construction may consist of seal ing soil gas entry areas and periodic ventilation of below-grade spaces and perimeter drain systems. It is relatively economical to provide for ventilation of perimeter drain systems or underslab gravel layers at the time of construction, compared to retr ofitting a structure after construction. Radon rarely accumulates to significant levels in above-grade, heated, and ventilated spaces. ROCKEFELLER ACQUISITIONS LLC GATEWAY AT PROSPPECT CTL|T PROJECT NO. FC10412-115 Field And Laboratory Investigations Subsurface conditions were further investigated by drilling thirteen exploratory borings at the approximate locations shown on Figure 1. The borings were drilled using a truck-mounted drill rig with 4-inch diameter continuous-flight auger. Our field representative observed drilling, logged the soils found in the borings, and obtained samples. Summary logs of the soils found in the borings and field penetration resistance values are presented on Figures 2 and 3. Samples of soil and bedrock were obtained during drilling by driving a modified California- type sampler (2.5 inch O.D.) into the subsoils and bedrock using a 140-pound hammer falling 30 inches. Samples recovered from the test holes were returned to our laboratory and visually classified by the geologist / geotechnical engineer. Laboratory testing included determination of moisture content and dry density, swell-consolidation characteristics, Atterberg limits, particle-size analysis, and water soluble sulfate content. Laboratory test results are presented in Appendix A. Subsurface Conditions The subsurface conditions encountered in our borings were variable across the site. In general, the soils encountered in our borings consisted of 5 to 12 feet of sandy clay over clayey to gravelly sand and sandy gravel . Claystone bedrock was encountered in seven borings at 16 to 24 feet and extended to the maximum depths explored. Samples of the soils tested exhibited 2.5 percent swell or less. Further discussion of the subsurface conditions can be found on our logs (Figures 2 and 3) and in our laboratory testing (Appendix A). Groundwater was encountered during drilling at depths ranging from 6 to 14 feet below the existing ground surface. When measured several days later, groundwater was encountered at depths of 5 to 8½ feet in all of the bo rings. We recommend a minimum 3-foot separation (preferably 5 feet) between foundations and slabs , and groundwater. This may limit basemen t potential for much of the site unless groundwater mitigation efforts are made. Groundwater will likely be encountered in deep utility excavations; dewatering will be necessary. Further monitoring of groundwater levels is recommended. ROCKEFELLER ACQUISITIONS LLC GATEWAY AT PROSPPECT CTL|T PROJECT NO. FC10412-115 Development Recommendations Appropriate planning, design, and construction will be necessary to address the aforementioned hazards. Adjustment of site grades, use of non -basement residences, and installation of active underdrain systems should mitigate shallow groundwater issues. The following sections discuss site development recommendations considering the current development plan. Dewatering and Stabilization Based on our measured water level s, groundwater will affect the planned development. Overlot grading or subsurface drainage systems can be used to control the water and reduce the risk of flooding basements, crawl spaces , and other improvements. Subsurface drainage can be accomplished by use of underdrains below sanitary sewer mains and interceptor drains upstream from the lots that connect to the underdrain. Underdrains below sanitary sewer mains can b e used in roadways upstream of other areas to lower and control groundwater. Groundwater will likely be encountered in utility excavations. Temporary construction dewatering systems will probably be needed to properly install deep utilities in areas. We believe that dewatering for excavations which penetrate less than 3 to 5 below the groundwater surface may be accomplished using conventional sump and pump methods in utility trenches. We recommend the sump pits be at least 3 feet deeper than the bottom of the deepest excavation. Deeper excavations may require more elaborate dewatering (such as well points). Soft, wet soils in foundation and utility excavations should be removed or stabilized. Excavations of soft soil should be filled with moisture -conditioned and compacted fill or approved import materials. Soft excavation bottoms can likely be stabilized by crowding crushed rock into the soils until firm. Acceptable rock materials include, but are not limited to, No. 2 and No. 57 rock. Crushed rock on a layer of geosynthetic grid or woven fabric can also be used, which should reduce the amount of aggregate needed to stabilize the subgrade. Typically, a biaxially woven fabric such as Mirafi 600x (or equal) or geogrid (such as Tensar BX1100 or equal) top ped with 8 to 12 inches of 1- to 5-inch crushed rock will provide a stable working surface. The City of Fort Collins, Larimer County, and/or the Colorado Department of Public Health and Environment may require dewatering permits. Our experience indicates p eriodic environmental ROCKEFELLER ACQUISITIONS LLC GATEWAY AT PROSPPECT CTL|T PROJECT NO. FC10412-115 testing is usually required with these permits, with reporting. Permitting requirements may also influence the construction schedule. We believe it is prudent to protect basements walls and crawl spaces from potential seepage. We believe installation of subsurface dra in systems can be considered as measures to possibly control shallow water. Drain system s include an interceptor drain, underdrains and foundation drains around foundation perimeters. Our firm generally advocates an under drain system below sanitary sewer mains and services to control groundwater that may accumulate in response to development. The underdrain also helps to control shallow water and unusually deep wetting, which can lead to higher frequency of heave -related foundation problems and frequent pumping from foundation drain s ystems. Considering the relatively shallow water across the majority of the site, we recommend an underdrain system as a means of mitigation. The underdrain can be perforated to help with seepa ge. The underdrain should consist of ¾ to 1½-inch clean, free-draining gravel surrounding a perforated PVC pipe. We believe use of perforated pipe below sanitary sewer mains is the most effective approach to control groundwater and collect water from pe rimeter drains. The pipe should be sized for anticipated flow. The line should consist of smooth, perforated or slotted, rigid PVC pipe placed at a grade of at least 0.5 percent. A concrete cutoff should be constructed around the sewer pipe and underdrain pipe immediately downstream of the point where the underdrain p ipe exits the sewer trench and transitions from perforated t o solid (Figures 5 and 6). Solid pipe should be used down gradient of this cutoff wall. The underdrains should be designed to dischar ge to a gravity outfall and be provided with a permanent concre te headwall and trash rack. If the underdrain discharges into a detention pond area, the risk of flood water backflow through the underdrain into basements should be carefully evaluated. A chec k valve or backflow preventer can be considered. The underdrain should be provided with clean-outs and be maintained. Where feasible, the underdrain services should be installed deep enough so that the lowest point of foundation drains can be connected to the underdrain service as a gravity outlet (Figure 4). If a gravity outfall is not possible, an alternative would be to out fall underdrains and interceptor drains to a wet well where water can be removed with a pump; maintenance should be expected with thi s option. It may not be practical to install underdrains at th is site if a gravity discharge is not available. It is possible a pumped system could be used, which would require long -term maintenance. Additional groundwater monitoring may be considered to evaluate seasonal fluctuations. ROCKEFELLER ACQUISITIONS LLC GATEWAY AT PROSPPECT CTL|T PROJECT NO. FC10412-115 Site Grading Prior to fill placement, the ground surface in areas to be filled should be stripped of debris, vegetation/organics, and other deleterious materials, scarified and moisture conditioned to between 0 and 3 percent above optimum for clay or within 2 percent of optimum for sand and gravel, and compacted to at least 95 percent of standard Proctor maximum dry density (ASTM D 698). Imported fill should ideally consist of soil which is similar to the on site soil. Potential fill materials should be submitted to our office fo r approval prior to importing to the site. The properties of fill will affect the performance of foundations, slabs -on-grade, utilities, pavements, flatwork, and other improvements. The on site soils are suitable for use as new fill provided they are substantially free of debris, vegetation/organics, and other deleterious materials. Fill should be placed in thin loose lifts, moisture conditioned , and compacted prior to placement of the next lift. Clay fill should be moisture conditioned to between 0 and 3 p ercent above optimum moisture content and compacted to at least 95 percent of standard Proctor maximum dry density (ASTM D 698). Sand and gravel fill should be moisture conditioned to within 2 percent of optimum moisture content and co mpacted similarly. The placement and compaction of fill should be observed and density tested by our representative during construction. Guideline site grading specifications are presented in Appendix B. Our experience indicates fill and backfill can comp ress, even if properly compacted to the criteria provided herein. Factors that influence the amount of settlement are depth of fill, material type, degree of compaction, amount of wetting , and time. The degree of compression of fill under its own weight will likely range from low for granular soils (½ percent or less) to moderate for clay/sand mixtures (1 to 2 percent). Settlement on the order of 1 to 2 percent of the fill depth due to self - weight of the fill should be anticipated. Slopes We recommend permanent cut and fill slopes be designed with a maximum grade of 4:1 (horizontal to vertical). If site constraints (property boundaries and streets) do not permit construction with recommended slopes, we should be contacted. Surface drainage should not be allowed to sheet flow across slopes or pond near the crest of slopes. All cut and fill slopes should ROCKEFELLER ACQUISITIONS LLC GATEWAY AT PROSPPECT CTL|T PROJECT NO. FC10412-115 be revegetated as soon as possible after grading to reduce potential for erosion problems. Erosion potential on the site is considered moderate, particularly on the eastern portion of the site where steeper slopes are present. Uncontrolled and concentrated surface runoff has the potential to create damaging erosion. Erosion potential will increase during construction but should return to pre- construction rates or less if proper grading practices, surface drainage design, and re-vegetation efforts are implemented. Excavation contractors should evaluate ground conditions and control slopes in accordance with OSHA criteria. Utility Construction We believe excavations for utility installation can be performed with heavy-duty trenchers, excavators, or large backhoes. Groundwater is shallow at this site and will likely be encountered during utility construction. Bracing and/or temporary dewatering may be required during utility construction. Dewatering wells may be necessary to lower the groundwater enough for planned sewer construction. Dewatering may be accomplished by sloping excavations to occasional sumps where water can be remov ed by pumping. The sumps should be several feet below the bottom of the excavations so that water is pumped down through the soils rather than up through the bottom of the excavations to reduce potential that the support capacity of the subsoils will be co mpromised. Utility trenches should be sloped or shored to meet local, state, and federal safety regulations. Excavation slopes specified by OSHA are dependent upon soil types and groundwater conditions encountered. We believe the soils at this site are Ty pe C, in that 1.5H:1V slopes are generally suitable for dry temporary excavations. Seepage and groundwater conditions in trenches may necessitate with flatter slopes. Initial trench excavations may be unstable and require flatter slopes than required by OSHA. Contractors should identify the soils encountered in the excavations and refer to OSHA standards to determine appropriate slopes. Excavations deeper than 20 feet should be designed by a professional engineer. The width of the top of an excavation may be limited in some areas. Bracing or “trench box” construction may be necessary. Bracing systems include sheet piling, braced sheeting, and others. Lateral loads on bracing depend on the depth of excavation, slope of excavation above the bracing, surface loads, hydrostatic pressures, and a llowable movement. For trench boxes and bracing allowed to move enough to mobilize the strength of the soils, with associated cracking of the ground surface, the “active” earth pressure conditions are appropriate for desig n. If movement is not ROCKEFELLER ACQUISITIONS LLC GATEWAY AT PROSPPECT CTL|T PROJECT NO. FC10412-115 tolerable, the “at rest” earth pressures are appropriate. We suggest an equivalent fluid density of 35 pcf for the “active” earth pressure condition and 50 pcf for the “at rest” earth pressure condition, assuming level backfill. These pressures do not include allowanc es for surcharge loading or for hydrostatic conditions. We are available to assist further with bracing design if desired. Water and sewer lines are usually constructed beneath paved roads. Compaction of trench backfill can have a significant effect on th e life and serviceability of pavements. Our experience indicates compacted trench backfill may settle 1 to 2 percent. More settlement may occur if wetting of the fill occurs. Trench backfill should be placed in thin loose lifts, moisture-conditioned, and compacted as recommended in the Site Grading section of this report. The placement and compaction of backfill should be observed and tested by our firm during construction. Preliminary Pavement Recommendations Soils encountered will likely provide fair to poor subgrade support accordi ng to AASHTO criteria. Any fill material used is assumed to have equal or better properties than the on site soil. We judge the risk of pavement distress due to expansive soils is low at this site. Preliminary guidelines for pavement systems on this site are provided. Final pavement sections should be determined based on a design level geotechnical investigation and anticipated frequency of load applications on the pavement during the desired design life. Flexible hot mixed asphaltic pavement (HMA) over aggregate base course (ABC) or rigid Portland cement concrete (PCC) pavements can be used at this site for automobile and light truck traffic use. Rigid pavements are recommended in any areas subject to heavy truck traffic. We anticipate asphalt pavement sections for local residential streets will be on the order of 6 inches of HMA over 8 inches of ABC. Collectors and other higher volume pavement will likely require thicker pavement sections, estimated on the order 6 to 8 inches HMA over 8 inches of ABC. Portland cement concrete (PCC) pavement are an alternative in areas subject to any heavy truck traffic such as garbage and heavy delivery trucks. We anticipate the use of 6 to 7 inche s of PCC. Preliminary Recommendations for Structures The following discussion is preliminary and not intended for design or construction. Recommendations provided here are general and for planning purposes only. After grading is ROCKEFELLER ACQUISITIONS LLC GATEWAY AT PROSPPECT CTL|T PROJECT NO. FC10412-115 completed, a design level geotechnical investigation should be conducted which provides foundation recommendations and design criteria for the planned construction. Foundations Subsurface conditions encountered in our borings were relatively consistent. We judge that spread footing founda tions are likely appropriate for homes at this site. The developer should plan for a separation of 3 to 5 feet between bottom of footings and groundwater. Stabilization in areas of soft soils may be possible. Stabilization may consist of placement of gra nular fill below footings. Areas of substantially soft soils may require additional measures. Floor Systems and Slab-on-Grade Construction Soils encountered in our borings were generally low -swelling or non-expansive. We judge low risk of poor basement slab-on-grade performance. Slab -on-grade floors may still experience some movements. Structurally supported floors are typically us ed for first floor living areas (walkout basements) or where movement is unacceptable. Below-Grade Construction We recommend a minimum 3-foot separation (preferably 5 feet) between the bottom of footing and groundwater. Because of the shallow groundwater typical basement construction may not be possible in some areas. If basements are desired, grade will have to be raised or groundwater controlled to permanently maintain this separation. Found ations will need reinforcement and design to resist lateral ear th pressure normal for this area. Below grade spaces should have perimeter drain systems that connect to sumps for pumping to the ground surface in a well-drained area. Surface Drainage The performance of improvements will be influenced by surface drai nage. The ground surface around proposed structures should be shaped to provide runoff of surface water away from the structure and off pavements. We generally recommend slopes of at least 12 inches in the first 10 feet where practical in the landscaping areas surrounding structures. There are practical ROCKEFELLER ACQUISITIONS LLC GATEWAY AT PROSPPECT CTL|T PROJECT NO. FC10412-115 limitations on achieving these slopes. Irrigation should be minimized to co ntrol wetting. Roof downspouts should discharge beyond the limits of backfill. Water should not be allowed to pond on or adjacent to pavements. Proper control of surface runoff is also important to limit the erosion of surface soils. Sheet flow should not be directed over unprotected slopes. Water should not be allowed to pond at the crest of slopes. Permanent slopes should be re -vegetated to reduce erosion. Water can follow poorly compacted fill behind curb and gutter and in utility trenches. This water can soften fill and undermine the p erformance of the roadways, flatwork, and foundations. We recommend compactive effort be used in placement of all fill. General Design Considerations Exterior sidewalks and pavements supported above the onsite clays are subject to post construction movement. Flat grades should be avoided to prevent possible ponding, particularly next to the building due to soil movement. Positive grades away from the buildings should be used for sidewalks and flatwork around the perimeter of the buildings in order to reduce the possibility of lifting of this flatwork, resulting in ponding next to the structures. Where movement of the flatwork is objectionable, procedures recommended for on-grade floor slabs should be considered. Joints next to buildings should be thoroughly sealed to prevent the infiltrat ion of surface water. Where concrete pave ment is used, joints should also be sealed to reduce the infiltration of water. Since some post construction movement of pavement and flatwork may occur, joints around the buildings should be periodically observed and resealed where necessary. Roof drains should be discharged well away from the structures, preferably by closed pipe systems. Where roof drains are allowed to discharge on concrete flatwork or pavement areas next to the structures, care should be tak en to ensure the area is as water-tight as practical to eliminate the infiltration of this water next to the buildings. Recommended Future Investigations Based on the results of this investigation and the proposed development, we recommend the following investigations be performed: ROCKEFELLER ACQUISITIONS LLC GATEWAY AT PROSPPECT CTL|T PROJECT NO. FC10412-115 1. Review of final site grading plans by our firm; 2. Additional groundwater monitoring ; 3. Construction testing and observation for site development; 4. Subgrade investigation and pavement design after site grading is complete; 5. Design-level soils and foundation investigations after grading; and 6. Construction testing and observation for residential building construction and paving. Limitations Our exploratory borings were located to obtain preliminary subsoil data indicative of conditions on this site. Although our borings were spaced to obtain a reasonably accurate picture of subsurface conditions, variations in the subsoils not indicated in our borings are always possible. We believe this investigation was conducted in a manner consistent with that level of skill and care ordinarily used by members of the profession currently practicing under similar conditio ns in the locality of this project. N o warranty, express or implied, is made. This report was prepared from data developed during our field exploration, laboratory testing, engineering analysis, and experience with similar conditions. The recommendations contained in this report were based upon our understanding of the planned construction. If plans change or differ from the assumptions presented herein, we should be contacted to review our recommendations. If we can be of further service in discussing the contents of this report or in the analysis of the building and pavement from the geotechnical point of view, please call. Very truly yours, CTL|THOMPSON, INC. Spencer Schram, PE R.B. "Chip" Leadbetter, III, P.E. Geotechnical Project Manager Senior Geotechnical Engineer TH-1 TH-2TH-3TH-4TH-5TH-6TH-7TH-8TH-9TH-10TH-12TH-13TH-11East Prospect RoadLEGEND:INDICATES APPROXIMATELOCATION OF EXPLORATORYBORINGTH-1I-25SITE E. MULBERRY ST.E. PROSPECT RD.TIMBERLINE FIGURE 1Locations ofExploratoryBoringsROCKEFELLER ACQUISITION LLCGATEWAY AT PROSPECTCTL I T PROJECT NO. FC10412-1150150'75'APPROXIMATESCALE: 1"=150'VICINITY MAPFORT COLLINS, COLORADONOT TO SCALE 4,865 4,870 4,875 4,880 4,885 4,890 4,895 4,900 4,905 4,910 4,865 4,870 4,875 4,880 4,885 4,890 4,895 4,900 4,905 4,910 14/12 3/12 40/12 WC=25.7 DD=92 SW=0.8 WC=25.7 DD=92 SW=0.8 TH-1 El. 4908.7 13/12 10/12 14/12 WC=20.1 DD=96 SW=0.0 -200=57 WC=8.8 -200=7 WC=20.1 DD=96 SW=0.0 -200=57 WC=8.8 -200=7 TH-2 El. 4909.0 0/12 12/12 10/12 37/12 50/2 WC=22.2 LL=24 PI=7 -200=47 WC=22.2 LL=24 PI=7 -200=47 TH-3 El. 4908.5 1/12 4/12 16/12 40/12 WC=30.5 DD=86 SW=0.0 WC=30.5 DD=86 SW=0.0 TH-4 El. 4908.6 6/12 1/12 19/12 TH-5 El. 4908.0 PRACTICAL DRILL REFUSAL. DRIVE SAMPLE. THE SYMBOL 14/12 INDICATES 14 BLOWS OF A 140-POUND HAMMER FALLING 30 INCHES WERE REQUIRED TO DRIVE A 2.5-INCH O.D. SAMPLER 12 INCHES.ELEVATION - FEETFIGURE 2ELEVATION - FEETWATER LEVEL MEASURED SEVERAL DAYS AFTER DRILLING. SAND, CLAYEY, WITH OCCASIONAL GRAVEL, MOIST TO WET, VERY LOOSE TO MEDIUM DENSE, BROWN, GRAY (SC) 2. 3. CLAY, SANDY, MOIST TO VERY MOIST, VERY SOFT TO VERY STIFF, LIGHT TO DARK BROWN, GRAY (CL) THE BORINGS WERE DRILLED ON OCTOBER 14 AND OCTOBER 18, 2022 USING 4-INCH DIAMETER CONTINUOUS-FLIGHT AUGERS AND A TRUCK-MOUNTED DRILL RIG. 1. LEGEND: NOTES: GRAVEL, SANDY, CLAYEY, VERY MOIST TO WET, LOOSE TO VERY DENSE, BROWN, GRAY CLAYSTONE, SILTY, MOIST TO VERY MOIST, HARD TO VERY HARD, DARK GRAY WATER LEVEL MEASURED AT TIME OF DRILLING. BORING ELEVATIONS WERE SURVEYED BY A REPRESENTATIVE OF THE CLIENTS. THESE LOGS ARE SUBJECT TO THE EXPLANATIONS, LIMITATIONS AND CONCLUSIONS IN THIS REPORT. 4. Summary Logs of Exploratory Borings WC DD SW -200 LL PI UC SS - - - - - - - - INDICATES MOISTURE CONTENT (%). INDICATES DRY DENSITY (PCF). INDICATES SWELL WHEN WETTED UNDER OVERBURDEN PRESSURE (%). INDICATES PASSING NO. 200 SIEVE (%). INDICATES LIQUID LIMIT. INDICATES PLASTICITY INDEX. INDICATES UNCONFINED COMPRESSIVE STRENGTH (PSF). INDICATES SOLUBLE SULFATE CONTENT (%). DRIVE SAMPLE. THE SYMBOL 40/12 INDICATES 40 BLOWS OF A 140-POUND HAMMER FALLING 30 INCHES WERE REQUIRED TO DRIVE A 2.0-INCH O.D. SAMPLER 12 INCHES. ROCKEFELLER ACQUISITION LLC GATEWAY AT PROSPECT CTL | T PROJECT NO. FC10412-115 4,870 4,875 4,880 4,885 4,890 4,895 4,900 4,905 4,910 4,870 4,875 4,880 4,885 4,890 4,895 4,900 4,905 4,910 3/12 11/12 8/12 11/12 50/4 WC=23.9 DD=93 SW=0.0 WC=24.0 -200=87 WC=23.9 DD=93 SW=0.0 WC=24.0 -200=87 TH-6 El. 4907.5 11/12 1/12 35/12 TH-7 El. 4907.1 13/12 1/12 16/12 50/5 WC=24.7 DD=95 SW=1.0 WC=24.7 DD=95 SW=1.0 TH-8 El. 4906.3 15/12 8/12 13/12 37/12 TH-9 El. 4905.4 11/12 2/12 6/12 50/8 50/6 50/4 WC=20.8 DD=102 SW=2.5 WC=21.0 DD=107 -200=55 WC=20.8 DD=102 SW=2.5 WC=21.0 DD=107 -200=55 TH-10 El. 4904.7 16/12 5/12 14/12 WC=22.5 DD=97 SW=1.7 LL=39 PI=11 WC=22.5 DD=97 SW=1.7 LL=39 PI=11 TH-11 El. 4908.1 22/12 12/12 6/12 WC=34.2 DD=90 LL=39 PI=5 -200=95 WC=19.3 DD=99 SW=0.1 WC=34.2 DD=90 LL=39 PI=5 -200=95 WC=19.3 DD=99 SW=0.1 TH-12 El. 4904.3 10/12 1/12 13/12 WC=22.9 DD=96 SW=0.2 LL=40 PI=13 WC=22.9 DD=96 SW=0.2 LL=40 PI=13 TH-13 El. 4908.0 ELEVATION - FEETSummary Logs of Exploratory BoringsELEVATION - FEETFIGURE 3 ROCKEFELLER ACQUISITION LLC GATEWAY AT PROSPECT CTL | T PROJECT NO. FC10412-115 GROUNDSURFACEFOUNDATIONDRAIN TRENCHBASEMENT EXCAVATION(MINIMUM 3' ABOVEGROUND WATER LEVEL)VERIFY ELEVATION OF UNDERDRAINWILL PROVIDE ADEQUATE DROPFOUNDATION DRAIN TO UNDERDRAIN,PARTICULARLY WHERE DEEPEREXCAVATIONS OCCUR (WHERESTRUCTURAL FLOORS ARE PLANNED).EXISTINGUNDERDRAINSERVICEUNDERDRAINSANITARYSEWERMAINSEWERSERVICETrenchBackfillPROPOSED STREETFIGURE 4 Conceptual Underdrain DetailROCKEFELLER ACQUISITION LLCGATEWAY AT PROSPECTCTL I T PROJECT NO. FC10412-115 Underdrain Connection Detail FIGURE 5 ROCKEFELLER ACQUISITION LLC GATEWAY AT PROSPECT CTL I T PROJECT NO. FC10412-115 PERFORATED UNDERDRAIN PIPE GRAVEL ENVELOPE SANITARY SEWER SANITARY SEWER BEDDING SOLID UNDERDRAIN PIPE TO OUTFALL LOCATION POUR CONCRETE NEAT - AGAINST EXCAVATION WALL AND SANITARY SEWER BEDDING MIN. 12" TO 18" (BACKHOE BUCKET WIDTH) NOTE: THE CONCRETE CUTOFF WALL SHOULD EXTEND INTO THE UNDISTURBED SOILS OUTSIDE THE UNDERDRAIN AND SANITARY SEWER TRENCH A MINIMU DISTANCE OF 12 INCHES. FIGURE 6 Underdrain Cutoff Wall ROCKEFELLER ACQUISITION LLC GATEWAY AT PROSPECT CTL I T PROJECT NO. FC10412-115 APPENDIX A LABORATORY TEST RESULTS TABLE A-I: SUMMARY OF LABORATORY TESTING Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT=92 PCF From TH - 1 AT 2 FEET MOISTURE CONTENT=25.7 % Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT=96 PCF From TH - 2 AT 2 FEET MOISTURE CONTENT=20.1 % ROCKEFELLER ACQUISITION LLC GATEWAY AT PROSPECT CTL | T PROJECT NO. FC10412-115 APPLIED PRESSURE - KSF APPLIED PRESSURE -KSFCOMPRESSION % EXPANSIONSwell Consolidation FIGURE A-1COMPRESSION % EXPANSION-4 -3 -2 -1 0 1 2 3 EXPANSION UNDER CONSTANT PRESSURE DUE TO WETTING -4 -3 -2 -1 0 1 2 3 NO MOVEMENT DUE TO WETTING 0.1 1.0 10 100 0.1 1.0 10 100 Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT=86 PCF From TH - 4 AT 4 FEET MOISTURE CONTENT=30.5 % Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT=93 PCF From TH - 6 AT 4 FEET MOISTURE CONTENT=23.9 % ROCKEFELLER ACQUISITIONS LLC GATEWAY AT PROSPECT CTL | T PROJECT NO. FC10412-115 APPLIED PRESSURE - KSF APPLIED PRESSURE -KSFCOMPRESSION % EXPANSIONSwell Consolidation FIGURE A-2COMPRESSION % EXPANSION-4 -3 -2 -1 0 1 2 3 NO MOVEMENT DUE TO WETTING -4 -3 -2 -1 0 1 2 3 NO MOVEMENT DUE TO WETTING 0.1 1.0 10 100 0.1 1.0 10 100 Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT=95 PCF From TH - 8 AT 2 FEET MOISTURE CONTENT=24.7 % Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT=102 PCF From TH - 10 AT 4 FEET MOISTURE CONTENT=20.8 % ROCKEFELLER ACQUISITIONS LLC GATEWAY AT PROSPECT CTL | T PROJECT NO. FC10412-115 APPLIED PRESSURE - KSF APPLIED PRESSURE -KSFCOMPRESSION % EXPANSIONSwell Consolidation FIGURE A-3COMPRESSION % EXPANSION-4 -3 -2 -1 0 1 2 3 EXPANSION UNDER CONSTANT PRESSURE DUE TO WETTING -4 -3 -2 -1 0 1 2 3 EXPANSION UNDER CONSTANT PRESSURE DUE TO WETTING 0.1 1.0 10 100 0.1 1.0 10 100 Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT=97 PCF From TH - 11 AT 2 FEET MOISTURE CONTENT=22.5 % Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT=99 PCF From TH - 12 AT 4 FEET MOISTURE CONTENT=19.3 % ROCKEFELLER ACQUISITIONS LLC GATEWAY AT PROSPECT CTL | T PROJECT NO. FC10412-115 APPLIED PRESSURE - KSF APPLIED PRESSURE -KSFCOMPRESSION % EXPANSIONSwell Consolidation FIGURE A-4COMPRESSION % EXPANSION-4 -3 -2 -1 0 1 2 3 EXPANSION UNDER CONSTANT PRESSURE DUE TO WETTING -4 -3 -2 -1 0 1 2 3 EXPANSION UNDER CONSTANT PRESSURE DUE TO WETTING 0.1 1.0 10 100 0.1 1.0 10 100 Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT=96 PCF From TH - 13 AT 2 FEET MOISTURE CONTENT=22.9 % ROCKEFELLER ACQUISITIONS LLC GATEWAY AT PROSPECT CTL | T PROJECT NO. FC10412-115 APPLIED PRESSURE -KSFCOMPRESSION % EXPANSIONSwell Consolidation Test Results FIGURE A-5 -8 -7 -6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6 7 EXPANSION UNDER CONSTANT PRESSURE DUE TO WETTING 0.1 1.0 10 100 Sample of SAND, GRAVELLY (SP)GRAVEL 17 %SAND 76 % From TH - 2 AT 14 FEET SILT & CLAY 7 %LIQUID LIMIT % PLASTICITY INDEX % Sample of CLAY, SANDY (CL)GRAVEL 2 %SAND 43 % From TH - 10 AT 14 FEET SILT & CLAY 55 %LIQUID LIMIT % PLASTICITY INDEX % ROCKEFELLER ACQUISITIONS LLC GATEWAY AT PROSPECT CTL | T PROJECT NO. FC10412-115 FIGURE A-6 Gradation Test Results 0.002 15 MIN. .005 60 MIN. .009 19 MIN. .019 4 MIN. .037 1 MIN. .074 *200 .149 *100 .297 *50 0.42 *40 .590 *30 1.19 *16 2.0 *10 2.38 *8 4.76 *4 9.52 3/8" 19.1 3/4" 36.1 1½" 76.2 3" 127 5" 152 6" 200 8" .001 45 MIN. 0 10 20 30 40 50 60 70 80 90 100 CLAY (PLASTIC) TO SILT (NON-PLASTIC)SANDS FINE MEDIUM COARSE GRAVEL FINE COARSE COBBLES DIAMETER OF PARTICLE IN MILLIMETERS 25 HR.7 HR. HYDROMETER ANALYSIS SIEVE ANALYSIS TIME READINGS U.S. STANDARD SERIES CLEAR SQUARE OPENINGS PERCENT PASSING0 10 20 30 50 60 70 80 90 100 PERCENT RETAINED40 0.002 15 MIN. .005 60 MIN. .009 19 MIN. .019 4 MIN. .037 1 MIN. .074 *200 .149 *100 .297 *50 0.42 *40 .590 *30 1.19 *16 2.0 *10 2.38 *8 4.76 *4 9.52 3/8" 19.1 3/4" 36.1 1½" 76.2 3" 127 5" 152 6" 200 8" .001 45 MIN. 0 10 20 30 40 50 60 70 80 90 100 CLAY (PLASTIC) TO SILT (NON-PLASTIC)SANDS FINE MEDIUM COARSE GRAVEL FINE COARSE COBBLES DIAMETER OF PARTICLE IN MILLIMETERS 25 HR.7 HR. HYDROMETER ANALYSIS SIEVE ANALYSIS TIME READINGS U.S. STANDARD SERIES CLEAR SQUARE OPENINGS PERCENT PASSINGPERCENT RETAINED0 10 20 30 40 50 60 70 80 90 100 PASSING MOISTURE DRY LIQUID PLASTICITY APPLIED NO. 200 DEPTH CONTENT DENSITY LIMIT INDEX SWELL* PRESSURE SIEVE BORING (FEET)(%)(PCF)(%)(PSF)(%)DESCRIPTION TH-1 2 25.7 92 0.8 200 CLAY, SANDY (CL) TH-2 2 20.1 96 0.0 200 57 CLAY, SANDY (CL) TH-2 14 8.8 7 SAND, GRAVELLY (SP) TH-3 9 22.2 24 7 47 SAND, CLAYEY (SC) TH-4 4 30.5 86 0.0 500 CLAY, SANDY (CL) TH-6 4 23.9 93 0.0 500 CLAY, SANDY (CL) TH-6 9 24.0 87 CLAY, SANDY (CL) TH-8 2 24.7 95 1.0 200 CLAY, SANDY (CL) TH-10 4 20.8 102 2.5 500 CLAY, SANDY (CL) TH-10 14 21.0 107 55 CLAY, SANDY (CL) TH-11 2 22.5 97 1.7 500 CLAY, SANDY (CL) TH-11 4 39 11 CLAY, SANDY (CL) TH-12 2 34.2 90 39 5 95 CLAY, SANDY (CL) TH-12 4 19.3 99 0.1 500 CLAY, SANDY (CL) TH-13 2 22.9 96 0.2 500 CLAY, SANDY (CL) TH-13 4 40 13 CLAY, SANDY (CL) SWELL TEST RESULTS* TABLE A-I SUMMARY OF LABORATORY TESTING ATTERBERG LIMITS Page 1 of 1 * NEGATIVE VALUE INDICATES COMPRESSION. ROCKEFELLER ACQUISITIONS LLC GATEWAY AT PROSPECT CTL|T PROJECT NO. FC10412-115 APPENDIX B GUIDELINE SITE GRADING SPECIFICATIONS ROCKEFELLER ACQUISITIONS LLC GATEWAY AT PROSPPECT CTL|T PROJECT NO. FC10412-115 Appendix B-1 GUIDELINE SITE GRADING SPECIFICATIONS 1. DESCRIPTION This item shall consist of the excavation, transportation, placement and compaction of materials from locations indicated on the plans, or staked by the Engineer, as necessary to achieve preliminary street and overlot elevations. These specifications shall also apply to compaction of excess cut materials that may be placed outside of the development boundaries. 2. GENERAL The Soils Engineer shall be the Owner's representative. The So ils Engineer shall approve fill materials, method of placement, moisture contents and percent compaction, and shall give written approval of the completed fill. 3. CLEARING JOB SITE The Contractor shall remove all vegetation and debris before excavation or fill placement is begun. The Contractor shall dispose of the cleared material to provide the Owner with a clean, neat appearing job site. Cleared material shall not be placed in areas to receive fill or where the material will support structures of any kind. 4. SCARIFYING AREA TO BE FILLED All topsoil and vegetable matter shall be removed from the ground surface upon which fill is to be placed. The surface shall then be plowed or scarified until the surface is free from ruts, hummocks or other uneven features, which would prevent uniform compaction. 5. COMPACTING AREA TO BE FILLED After the foundation for the fill has been cleared and scarified, it shall be disked or bladed until it is free from large clods, brought to the proper moisture content (0 to 3 percent above optimum moisture content for clays and within 2 percent of optimum moisture content for sands) and compacted to not less than 95 percent of maximum dry density as determined in accordance with ASTM D698. 6. FILL MATERIALS Fill soils shall be free from organics, debris, or other deleterious substances, and shall not contain rocks or lumps having a diameter greater than six (6) inches. Fill materials shall be obtained from cut areas shown on the plans or staked in the field by the Engineer. ROCKEFELLER ACQUISITIONS LLC GATEWAY AT PROSPPECT CTL|T PROJECT NO. FC10412-115 Appendix B-2 On-site materials classifying as CL, CH, SC, SM, SW, SP, GP, GC, and GM are acceptable. Concrete, asphalt, organic matter and other deleterious materials or debris shall not be used as fill. 7. MOISTURE CONTENT AND DENSITY Fill material shall be moisture conditioned and compacted to the criteria in the table, below. Maximum density and optimum moisture content shall be determined from the appropriate Proctor compaction tests. Sufficient laboratory compaction tests shall be made to determine the optimum moisture content for the various soils encountered in borrow areas. FILL COMPACTION AND MOISTURE REQUIREMENTS Soil Type Depth from Overlot Grade (feet) Moisture Requirement (% from optimum) Density Requirement Clay 0 to 20 feet +1 to +4 95% of ASTM D 698 Sand -2 to +2 95% of ASTM D 698 Clay Greater than 20 feet -2 to +1 98% of ASTM D 698 Sand -2 to +1 95% of ASTM D 1557 The Contractor may be required to add moisture to the excavation materials in the borrow area if, in the opinion of the Soils Engineer, it is not possible to obtain uniform moisture content by adding water on the fill surface. The Contractor may be required to rake or disc the fill soils to provide uniform moisture content through the soils. The application of water to embankment materials shall be made with any type of watering equipment approved by the Soils Engineer, which will give the desired results. Water jets from the spreader shall not be directed at the embankment with such force that fill materials are washed out. Should too much water be added to any part of the fill, such that the material is too wet to permit the desired compaction from being obtained, rolling and all work on that section of the fill shall be delayed until the material has been allowed to dry to the required moisture content. The Contractor will be permitted to rework wet material in an approved manner to hasten its drying. ROCKEFELLER ACQUISITIONS LLC GATEWAY AT PROSPPECT CTL|T PROJECT NO. FC10412-115 Appendix B-3 8. COMPACTION OF FILL AREAS Selected fill material shall be placed and mixed in evenly spread layers. After each fill layer has been placed, it shall be uniformly compacted to not less than the specified percentage of maximum density. Fill shall be compacted to the criteria above. At the option of the Soils Engineer, soils classifying as SW, GP, GC, or GM may be compacted to 95 percent of maximum density as determined in accordance with ASTM D 1557 or 70 percent relative density for cohesionless sand soils. Fill materials shall be placed such that the thickness of loose materials does not exceed 12 inches and the compacted lift thickness does not exceed 6 inches. Compaction as specified above, shall be obtained by the use of sheepsfoot rollers, multiple-wheel pneumatic-tired rollers, or other equipment approved by the Engineer for soils classifying as CL, CH, or SC. Granular fill shall be compacted using vibratory equipment or other equipment approved by the Soils Engineer. Compaction shall be accomplished while the fill material is at the specified moisture content. Compaction of each layer shall be continuous over the entire area. Compaction equipment shall make sufficient trips to ensure that the required density is obtained. 9. COMPACTION OF SLOPES Fill slopes shall be compacted by means of sheepsfoot rollers or other suitable equipment. Compaction operations shall be continued until slopes are stable, but not too dense for planting, and there is not appreciable amount of loose soils on the slopes. Compaction of slopes may be done progressively in increments of three to five feet (3' to 5') in height or after the fill is brought to its total height. Permanent fill slopes shall not exceed 3:1 (horizontal to vertical). 10. PLACEMENT OF FILL ON NATURAL SLOPES Where natural slopes are steeper than 20 percent in grade and the placement of fill is required, benches shall be cut at the rate of one bench for each 5 feet in height (minimum of two benches). Benches shall be at least 10 feet in width. Larger bench widths may be required by the Engineer. Fill shall be placed on completed benches as outlined within this specification. 11. DENSITY TESTS Field density tests shall be made by the Soils Engineer at locations and depths of his choosing. Where sheepsfoot rollers are used, the soil may be disturbed to a depth of several inches. Density tests shall be taken in compacted material below the disturbed surface. When density tests indicate that the density or moisture content of any layer of fill or portion thereof is not within specification, the particular layer or portion shall be reworked until the required density or moisture content has been achieved. ROCKEFELLER ACQUISITIONS LLC GATEWAY AT PROSPPECT CTL|T PROJECT NO. FC10412-115 Appendix B-4 12. SEASONAL LIMITS No fill material shall be placed, spread or rolled while it is frozen, thawing, or during unfavorable weather conditions. When work is interrupted by heavy precipitation, fill operations shall not be resumed until the Soils Engineer indicates that the moisture content and density of previously placed materials are as specified. 13. NOTICE REGARDING START OF GRADING The Contractor shall submit notification to the Soils Eng ineer and Owner advising them of the start of grading operations at least three (3) days in advance of the starting date. Notification shall also be submitted at least 3 days in advance of any resumption dates when grading operations have been stopped for any reason other than adverse weather conditions. 14. REPORTING OF FIELD DENSITY TESTS Density tests made by the Soils Engineer, as specified under "Density Tests" above, shall be submitted progressively to the Owner. Dry density, moisture content, and percentage compaction shall be reported for each test taken. 15. DECLARATION REGARDING COMPLETED FILL The Soils Engineer shall provide a written declaration stating that the site was filled with acceptable materials, and was placed in general accordance with the specifications.