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THE GREEN SOLUTION - PDP/FDP - FDP150045 - SUBMITTAL DOCUMENTS - ROUND 3 - DRAINAGE REPORT
FINAL DRAINAGE REPORT FOR THE GREEN SOLUTION 810 NORTH COLLEGE AVENUE FORT COLLINS, COLORADO LARIMER COUNTY April 27, 2016 Prepared for: The Green Solution 700 17 th Street, Suite 1610 Denver, CO 80202 Contact: Kyle Speidell 720.399.6840 Prepared By: Manhard Consulting, Ltd. 8008 East Arapahoe Ct., Suite 110 Centennial, Colorado 80112 Contact: Daniel Madruga (303) 531-3400 TGSFCCO01 i Engineer’s Statement: This Drainage Report for The Green Solution was prepared by me, or under my direct supervision, in accordance with the provisions of the City of Fort Collins Stormwater Criteria Manual and was designed to comply with the provisions thereof. I understand that the City of Fort Collins does not and will not, assume liability for drainage facilities designed by others. ___________________________________ Daniel J. Madruga, PE Registered Professional Engineer State of Colorado No. 36834 ii Table of Contents INTRODUCTION Location ................................................................................................................................. 1 Site Description ..................................................................................................................... 1 Proposed Development ......................................................................................................... 1 DRAINAGE BASINS AND SUB-BASINS Overall Basin Description ...................................................................................................... 2 Drainage Patterns Through Property .................................................................................... 2 DESIGN CRITERIA Hydrologic Criteria ................................................................................................................. 2 DRAINAGE PLAN General Concept ................................................................................................................... 3 Specific Details ...................................................................................................................... 3 Storm Sewer .......................................................................................................................... 4 Maintenance and Inspection ................................................................................................. 4 CONCLUSION Compliance with Standards .................................................................................................. 5 Summary of Concept ............................................................................................................. 5 REFERENCES Appendix A FIRM Map Soils Map Drainage Maps Appendix B Hydrologic Calculations Appendix C Filterra Design Information Hydraulic Calculations Appendix D Geotechnical Report Appendix E Filterra Operations and Maintenance Manual iii Vicinity Map 1 INTRODUCTION This report presents The Green Solution drainage report and drainage system design. The design and analysis of this site has been performed in accordance with the Urban Drainage and Flood Control District (UDFCD) “Urban Storm Drainage Criteria Manual” along with City of Fort Collins Amendments. Drawings, tables, and design calculations are included in the appendices of this report. Location The proposed development is part of Section 1, Township 7 North, Range 69 West of the 6th Principal Meridian, City of Fort Collins, Larimer County, State of Colorado. More specifically it is located at 810 N College Avenue. Adjacent developments include an existing bowling alley to the north, an existing liquor store to the east, and an existing auto sales business to the south. Site Description The site is approximately 0.30 acres and the existing condition consists of a medical marijuana store and associated parking area. The topography for the site generally slopes from northwest to southeast at approximately 1.5%. Based on the USDA Web Soil Survey, the soils within the site are Nunn clay loam which falls into Hydrologic Soils Group Type C. There is very little existing vegetation on site. The site is located within the FEMA 100-year floodplain, Zone AE, as indicated on the Flood Insurance Rate Map, Panel Number 08069C0977G, revised June 17, 2008. Proposed Development The proposed project will expand an existing medical marijuana facility for use as a retail marijuana store. The existing parking area located between the building and N. College Avenue will be removed and replaced primarily with landscaping. A portion of the existing building and the asphalt to the east of the existing building will be demolished for the construction of the building addition. The change in coverage is summarized below: Pre-Development Post-Development Total Impervious Area 0.30 ac 0.21 ac Total Pervious Area 0.01 ac 0.10 ac Although the project includes an approximate 2,500 sf building addition, the impervious area for this project will decrease by approximately 3400 sf. It is intended that the finished floor elevation of the addition match the elevation of the existing building, which is 4968.9. The Base Flood Elevation (BFE) at the upstream side of the building is 4969.77. The total structure is to be dry-floodproofed, with flood resistant materials up to the Regulatory Flood Protection Elevation (RFPE), which is 4971.77, and floodproof doorways at the exterior walls of the building. 2 DRAINAGE BASINS AND SUB-BASINS Overall Basin Description Based on the Drainage Basin Master Plan, the site is located within the Dry Creek Drainage Basin, which is tributary to the Poudre River. More specifically, the site is located within Basin 517 of the Northeast College Corridor Outfall (NECCO). The land use in the Dry Creek Drainage Basin is primarily rangeland and irrigated hay meadows and pastures in the upper and middle portions of the basin. The majority of the lower basin, where the site is located, is developed and includes, commercial, industrial, and residential uses. Drainage Patterns Through Property The existing site drains from west to east toward a natural low point in the southeast corner of the site and continues to flow overland off-site to the east and eventually to the Josh Ames Ditch to the south. The existing flows are currently undetained and without water quality control on-site. DESIGN CRITERIA Hydrologic Criteria The Urban Drainage and Flood Control District (UDFCD) “Urban Storm Drainage Criteria Manual” along with City of Fort Collins Amendments were used for the storm drainage system design. Since the site falls within basin 517 of the Northeast College Corridor Outfall (NECCO), quantity and quality detention will be handled by a regional facility. The runoff rates for the existing conditions and the proposed conditions were calculated as follows: Design Rainfall: Rainfall data from The City of Fort Collins Amendments to the Urban Storm Drainage Criteria Manual was used to determine peak runoff rates for the 2-year (minor) and 100- year (major) storms. Runoff Calculation: Peak storm runoff is determined using the rational formula, Q = CIA: Q = storm runoff in CFS; C = runoff coefficient based on surface impermeability; I = rainfall intensity in inches per hour; and A = drainage basin area in acres. Runoff Coefficients (Table RO-11) and appropriate adjustment factors (Table RO-12) were used to develop runoff coefficients for the minor and major storm events. The runoff coefficients are weighted to more accurately reflect the runoff characteristics of the site. Time of Concentration is determined using the criteria in Section 2.4 of the UDFCD Criteria Manual. Per the direction of the City of Fort Collins, the time of concentration was determined for both the minor and major storm events by using the respective runoff coefficients as described above. Based on the time of concentration for each area, rainfall intensities were determined using the City of Fort Collins IDF Table, which is included in Appendix B. 3 The rational method (Q = CIA), as shown in the Urban Storm Drainage Criteria Manual, was used to calculate total runoff (Q) for the 2-year and 100-year storm events. Results are shown in the Appendix B and summarized below. Storm Event Pre-Development Post-Development 2-year, 1 hour Q(cfs) 0.82 0.61 100-year, 1 hour Q (cfs) 3.00 2.26 DRAINAGE PLAN General Concept Stormwater detention and water quality have been accounted for this site within the Northeast College Corridor Outfall (NECCO). A Low Impact Development (LID) system has been provided to meet the City of Fort Collins requirements. Sub basins A-1, A-2 and B-1 through B4, outlined below, will be directed to a Filterra biofitraltion system located on the southeast corner of the property. The area to be treated by the LID system is summarized as follows: Impervious area Overall Newly Developed Area (ac) 0.21 0.31 Area treated by LID (ac) 0.159 0.193 Percentage Treated 75.7% 62.3% Specific Details The proposed development has been divided into three major basins: Basin A, Basin B, and the OS Basin. A drainage map, presenting the drainage basin delineations as well as existing and proposed drainage facilities, can be found in Appendix A of this report. The following text generally describes basin conveyance to design points. Hydrologic calculations for each sub-basin are presented in the rational method SF-3 forms in Appendix B of this report. Sub-basin A-1, 0.056 acres, is located in the northwest corner of the property and consists of a portion of the proposed sidewalk and isolated parking space to the west. This flow will be conveyed through the cross pan on the north side of the parking area and ultimately to the LID system located in the southeast corner of the property. Sub-basin A-2, 0.027 acres, consists of the western portion of the parking area. This flow will be conveyed though a chase located in the southeastern corner of the parking area and ultimately to the LID system located in the southeast corner of the property. Sub-basin B-1, 0.110 acres, consists of the roof of the building and will be discharged at grade through four downspouts on the southern side of the building. This flow will be directed to the LID system located in the southeast corner of the property. Sub-basin B-2, 0.031 acres, consists of the landscaped area to the south of the building. This flow will be directed to the LID system in the southeast corner of the property. Sub-basin B-3, 0.031 acres, consists of the sidewalk along the eastern side of the building and trash enclosure area. This flow will be directed through an opening in the southern wall of the trash enclosure to the LID system located in the southeast corner of the property. 4 Sub-basin OS-1, 0.057 acres, consists of the landscaped area and sidewalk in the front of the building. This flows to an area drain in the southwest portion of the site and will be conveyed to a drywell along the south side of the property. Sub-basin OS-2, 0.01 acres, consists of proposed asphalt pavement area on the west edge of the property. This area will flow away from the site, matching existing drainage patterns. The Filterra system, which will act as the LID system for the site, is similar to bioretention in its function and application, but has been optimized for high volume/flow treatment and high pollutant removal. Stormwater runoff from Sub-basins A-1, A-2 and B-1 through B-3 enters the system through a curb inlet and flows through a specially designed filter media mixture contained inside the inlet box and to an underdrain system, where the treated water will be discharged to the existing stormwater system in N. College Ave. Once the Filterra system has reached its capacity, the additional runoff will bypass the Filterra system and discharge overland to the west along the historical drainage path for this site. Additional information can be found in Appendix C. Storm Sewer Due to the limited amount of storm sewer for this project, the capacity of the opening on the south side of the trash enclosure wall was determined using FlowMaster. By entering the physical properties of the wall opening, the maximum discharge for the 100-year storm event was determined. The outlet pipe from the Filterra system to the drywell was based on the maximum outflow from the Filterra system as determined by Contech’s analysis. The information about the Filterra system in Appendix C is a sample analysis on the largest Filterra system, from which they were able to extrapolate data for the smaller units. The Nyloplast inlet grate for the area drain (Basin OS-1) was sized to accept the anticipated flows from the 100-year storm event. The manufacturer’s inlet capacity chart has been provided. Refer to Appendix C for Hydraulic calculations and supporting documentation. Drywell A drywell was designed to accept the flows from the Filterra system and the minor storm event flows from the area drain (Basin OS-1) in the southwest corner of the site. Terracon Consultants performed a percolation test on site in the proposed drywell location. Refer to Appendix D for the Geotechnical Engineering Report dated April 8, 2016. Based on the calculations in Appendix B, the inflow from the area drain is 0.04 cfs for the 2-year storm. The maximum anticipated outflow from the Filterra system is 0.10 cfs. During a one hour storm, the volume of water flowing to the drywell is approximately 864 cf. Two 36” pipes will be used to store this volume before flowing to a manhole that will be used to collect sediment. The water will then flow into a second manhole, which will have an open bottom and act as the drywell to return water to the ground. Maintenance and Inspection The maintenance of the Filterra system will be completed by the supplier within the first year of operation. Beyond this period, the Filterra system should be inspected a minimum of twice annually for standing water, damage to the box structure or grate, and bypass. The mulch should be removed and replaced a minimum of once a year. At all times, the system should be kept clear of trash and other debris. The Operation and Maintenance manual have been included in Appendix E. 5 CONCLUSION Compliance with Standards The drainage system and LID system for the Green Solution site were designed to meet the City of Fort Collins’ drainage criteria. The site is located within a F.E.M.A. mapped floodplain, however the project does not require a map revision. The existing building and proposed addition will be floodproofed in accordance with F.E.M.A. and the City of Fort Collins standards. Summary of Concept The drainage system for the Green Solution site was designed to allow storm water to be safely conveyed through and away from the site without negatively impacting downstream or upstream properties beyond that imposed by the historic condition. All drainage facilities proposed with this development are private facilities and will be maintained by the owner. 6 REFERENCES 1. City of Fort Collins Amendments to the Urban Drainage and Flood Control District Criteria Manual, December, 2012. 2. Urban Drainage and Flood Control District, Denver, Colorado, Urban Storm Drainage Criteria Manual, Volumes 1, 2 & 3, June 2001. Appendix A FIRM Map Soils Map Drainage Maps Hydrologic Soil Group—Larimer County Area, Colorado Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 12/4/2015 Page 1 of 4 4494130 4494137 4494144 4494151 4494158 4494165 4494172 4494130 4494137 4494144 4494151 4494158 4494165 4494172 493518 493525 493532 493539 493546 493553 493560 493567 493574 493581 493588 493518 493525 493532 493539 493546 493553 493560 493567 493574 493581 493588 40° 35' 54'' N 105° 4' 35'' W 40° 35' 54'' N 105° 4' 32'' W 40° 35' 52'' N 105° 4' 35'' W 40° 35' 52'' N 105° 4' 32'' W N Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 13N WGS84 0 15 30 60 90 Feet 0 4 9 18 27 Meters Map Scale: 1:328 if printed on A landscape (11" x 8.5") sheet. MAP LEGEND MAP INFORMATION Area of Interest (AOI) Area of Interest (AOI) Soils Soil Rating Polygons A A/D B B/D C C/D D Not rated or not available Soil Rating Lines A A/D B B/D C C/D D Not rated or not available Soil Rating Points A A/D B B/D C C/D D Not rated or not available Water Features Streams and Canals Transportation Rails Interstate Highways US Routes Major Roads Local Roads Background Aerial Photography The soil surveys that comprise your AOI were mapped at 1:24,000. Warning: Soil Map may not be valid at this scale. Enlargement of maps beyond the scale of mapping can cause misunderstanding of the detail of mapping and accuracy of soil line placement. The maps do not show the small areas of contrasting soils that could have been shown at a more detailed scale. Please rely on the bar scale on each map sheet for map measurements. Source of Map: Natural Resources Conservation Service Web Soil Survey URL: http://websoilsurvey.nrcs.usda.gov Coordinate System: Web Mercator (EPSG:3857) Maps from the Web Soil Survey are based on the Web Mercator projection, which preserves direction and shape but distorts distance and area. A projection that preserves area, such as the Albers equal-area conic projection, should be used if more accurate calculations of distance or area are required. This product is generated from the USDA-NRCS certified data as of the version date(s) listed below. Soil Survey Area: Larimer County Area, Colorado Hydrologic Soil Group Hydrologic Soil Group— Summary by Map Unit — Larimer County Area, Colorado (CO644) Map unit symbol Map unit name Rating Acres in AOI Percent of AOI 73 Nunn clay loam, 0 to 1 percent slopes C 0.4 100.0% Totals for Area of Interest 0.4 100.0% Description Hydrologic soil groups are based on estimates of runoff potential. Soils are assigned to one of four groups according to the rate of water infiltration when the soils are not protected by vegetation, are thoroughly wet, and receive precipitation from long-duration storms. The soils in the United States are assigned to four groups (A, B, C, and D) and three dual classes (A/D, B/D, and C/D). The groups are defined as follows: Group A. Soils having a high infiltration rate (low runoff potential) when thoroughly wet. These consist mainly of deep, well drained to excessively drained sands or gravelly sands. These soils have a high rate of water transmission. Group B. Soils having a moderate infiltration rate when thoroughly wet. These consist chiefly of moderately deep or deep, moderately well drained or well drained soils that have moderately fine texture to moderately coarse texture. These soils have a moderate rate of water transmission. Group C. Soils having a slow infiltration rate when thoroughly wet. These consist chiefly of soils having a layer that impedes the downward movement of water or soils of moderately fine texture or fine texture. These soils have a slow rate of water transmission. Group D. Soils having a very slow infiltration rate (high runoff potential) when thoroughly wet. These consist chiefly of clays that have a high shrink-swell potential, soils that have a high water table, soils that have a claypan or clay layer at or near the surface, and soils that are shallow over nearly impervious material. These soils have a very slow rate of water transmission. If a soil is assigned to a dual hydrologic group (A/D, B/D, or C/D), the first letter is for drained areas and the second is for undrained areas. Only the soils that in their natural condition are in group D are assigned to dual classes. Rating Options Aggregation Method: Dominant Condition Component Percent Cutoff: None Specified Hydrologic Soil Group—Larimer County Area, Colorado Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 12/4/2015 Page 3 of 4 Tie-break Rule: Higher Hydrologic Soil Group—Larimer County Area, Colorado Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 12/4/2015 Page 4 of 4 E-1 0.31 AC. 0.93 0.97 1 EXISTING BOWLING ALLEY EXISTING LIQUOR STORE NORTH COLLEGE AVENUE EXISTING CAR SALES EXISTING BUILDING FF-4968.90 PROPOSED DRAINAGE BASIN DRAINAGE BASIN OUTLINE DESIGN POINT EXISTING FLOW PATH EXISTING STORM LEGEND 1 BASIN AREA AC. C2 C100 0 SCALE: 1"=10' 5 10 20 PROJ. MGR.: DRAWN BY: DATE: OF SHEET PROJ. ASSOC.: DATE REVISIONS DRAWN BY c 2016 MANHARD CONSULTING, LTD. ALL RIGHTS RESERVED TM EXISTING DRAINAGE PLAN THE GREEN SOLUTION 810 N COLLEGE AVENUE FORT COLLINS, CO TGSFCCO01 ---- 2/1/16 JAR JAR DJM Plotted: 2/2/2016 2:43 PM Dwg Name: P:\Tgsfcco01\Documents\StormWater Reports\Preliminary Stormwater Reports\EX DNG.dwg Updated By: jrentz NOTES: 1. ALL STREET, SANITARY SEWER, STORM SEWER AND WATER CONSTRUCTION SHALL CONFORM TO CITY STANDARDS AND SPECIFICATIONS CURRENT AT DATE OF EXECUTION OF THE DEVELOPMENT AGREEMENT PERTAINING TO THIS DEVELOPMENT. ANY CONSTRUCTION OCCURRING THREE YEARS AFTER THE EXECUTION OF THE DEVELOPMENT AGREEMENT SHALL REQUIRE RE-EXAMINATION OF THE PLANS BY THE DIRECTOR WHO MAY REQUIRE THAT THEY BE MADE TO CONFORM TO STANDARDS AND SPECIFICATIONS CURRENT AT THAT TIME. 2. THE TYPE, SIZE, LOCATION, AND NUMBER OF ALL KNOWN UNDERGROUND UTILITIES ARE APPROXIMATE AS SHOWN ON THE DRAWINGS. IT SHALL BE THE RESPONSIBILITY OF THE CONTRACTOR TO VERIFY THE EXISTENCE AND LOCATION OF ALL UNDERGROUND UTILITIES ALONG THE ROUTE OF THE WORK. BEFORE COMMENCING NEW CONSTRUCTION, THE CONTRACTOR SHALL BE RESPONSIBLE 1 2 3 4 5 6 EXISTING BOWLING ALLEY EXISTING LIQUOR STORE NORTH COLLEGE AVENUE EXISTING CAR SALES PROPOSED BUILDING EXPANSION FF=4968.90 EXISTING BUILDING FF-4968.90 8" x 16" WALL OPENING CHASE FILTERRA WATER QUALITY/ BIOFILTER VAULT FEMA 100-YEAR POUDRE RIVER FLOODPLAIN ZONE "AE" CONCRETE PAN 7 OS-1 0.06 AC. 0.22 0.25 A-2 0.02 AC. 0.74 0.79 B-1 0.11 AC. 0.95 1.00 B-3 0.01 AC. 0.87 0.92 B-2 0.03 AC. 0.10 0.13 A-1 0.06 AC. 0.81 0.86 OS-2 0.01 AC. 0.95 1.00 Appendix B Hydrologic Calculations RUNOFF COEFFICIENTS AND IMPERVIOUSNESS The Green Solution - Fort Collins 2/1/2016 Land Use Impervious 2-yr 5-yr 100-yr Paving 0.95 0.95 1.00 100% Sidewalk 0.95 0.95 1.00 100% Roofs 0.95 0.95 1.00 100% Lawns 0.1 0.10 0.13 0% Basin No Total Area Paved Area Roofed Area Lawn Area Composite Imperviousness (AC) (AC) (AC) (AC) 2 Year 5 Year 100 Year (%) E-1 0.19 0.12 0.06 0.01 0.91 0.91 0.96 95.2% ONSITE TOTAL 0.19 0.12 0.06 0.01 0.91 0.91 0.96 95.2% Runoff Coeff. Composite Runoff Coefficient The Green Solution - Fort Collins TIME OF CONCENTRATION JOB NO: DATE: 2/1/2016 PROJECT: TGSFCCO01 CALCULATED BY: JAR DESIGN STORM: 2 YEAR INITIAL/OVERLAND TRAVEL TIME FINAL TIME (ti) (tt) tc TRIBUTARY AREA C LENGTH SLOPE ti LENGTH SLOPE Conveyance VEL tt COMP. TOTAL (L/180)+10 BASINS Ac Ft % Min. Ft. % Coefficient fps Min. tc LENGTH Min. Min. (2) (3) (4) (5) (6) (7) (8) (9) (10) (11) (12) (13) (14) E-1 0.19 0.91 60 1.10 2.67 160 0.90 20 1.90 1.41 4.08 220 11.22 5.00 NOTES: Ti = [1.87 x (1.1 - CxC f) x L 0.5 ] / (S 0.33 ) *S IN %* V = (Cv) x (S w 0.5 ) Tt = L / (60 x V) TC Check = 10 + L/180 (Urbanized Basins Only) Tc Min = 5 Minutes (Per UDFCD 2.4.4) tc CHECK (URBANIZED BASINS) The Green Solution - Fort Collins TIME OF CONCENTRATION JOB NO: DATE: 2/1/2016 PROJECT: TGSFCCO01 CALCULATED BY: JAR DESIGN STORM: 100 YEAR INITIAL/OVERLAND TRAVEL TIME FINAL TIME (ti) (tt) tc TRIBUTARY AREA C100 LENGTH SLOPE ti LENGTH SLOPE Conveyance VEL tt COMP. TOTAL (L/180)+10 BASINS Ac Ft % Min. Ft. % Coefficient fps Min. tc LENGTH Min. Min. (2) (3) (4) (5) (6) (7) (8) (9) (10) (11) (12) (13) (14) E-1 0.19 0.91 60 1.10 2.67 160 0.90 20 1.90 1.41 4.08 220 11.22 5.00 NOTES: Ti = [1.87 x (1.1 - CxC f) x L 0.5 ] / (S 0.33 ) *S IN %* V = (Cv) x (S w 0.5 ) Tt = L / (60 x V) TC Check = 10 + L/180 (Urbanized Basins Only) Tc Min = 5 Minutes (Per UDFCD 2.4.4) tc CHECK (URBANIZED BASINS) DATE: 2/1/2016 JOB NO: CALCULATED BY: JAR PROJECT: TGSFCCO01 DIRECT RUNOFF TOTAL RUNOFF CARRYOVER Basin Design Area C2 C x A Tc Intensity Qd = CIA C x A Tc Intensity Qd = CIA C x A Tc Intensity Qd = CIA To Design Point (acres) (min) (in/hr) (cfs) (min) (in/hr) (cfs) (min) (in/hr) (cfs) Point E-1 1 0.19 0.91 0.17 5.00 2.88 0.50 TOTAL 0.50 NOTES: The Green Solution - Fort Collins 2-YEAR RUNOFF CALCULATIONS I values obtained from the City of Fort Collins IDF table DATE: 2/1/2016 JOB NO: CALCULATED BY: JAR PROJECT: TGSFCCO01 DIRECT RUNOFF TOTAL RUNOFF CARRYOVER Basin Design Area C100 C x A Tc Intensity Qd = CIA C x A Tc Intensity Qd = CIA C x A Tc Intensity Qd = CIA To Design Point (acres) (min) (in/hr) (cfs) (min) (in/hr) (cfs) (min) (in/hr) (cfs) Point E-1 1 0.19 0.96 0.18 5.00 9.95 1.80 TOTAL 1.80 NOTES: The Green Solution - Fort Collins 100-YEAR RUNOFF CALCULATIONS I values obtained from the City of Fort Collins IDF table RUNOFF COEFFICIENTS AND IMPERVIOUSNESS The Green Solution - Fort Collins 3/17/2016 Land Use Impervious 2-yr 5-yr 100-yr Pavement 0.95 0.95 1.00 100% Roof 0.95 0.95 1.00 100% Landscape 0.10 0.10 0.13 0% Soil Type = C Basin No Total Area Paved Area Roofed Area Lawn Area Composite Imperviousness (AC) (AC) (AC) (AC) 2 Year 5 Year 100 Year (%) A-1 0.056 0.047 0.000 0.009 0.81 0.81 0.86 83.9% A-2 0.023 0.017 0.000 0.006 0.74 0.74 0.79 75.5% SUBTOTAL 0.079 0.064 0.000 0.015 0.79 0.79 0.84 81.5% B-1 0.110 0.000 0.110 0.000 0.95 0.95 1.00 100.0% B-2 0.031 0.000 0.000 0.031 0.10 0.10 0.13 0.0% B-3 0.014 0.013 0.000 0.001 0.87 0.87 0.92 90.5% SUBTOTAL 0.155 0.013 0.110 0.032 0.77 0.77 0.82 79.1% OS-1 0.057 0.008 0.000 0.049 0.22 0.22 0.25 14.6% OS-2 0.012 0.012 0.000 0.000 0.95 0.95 1.00 100.0% SUBTOTAL 0.069 0.020 0.000 0.049 0.35 0.35 0.38 29.0% TOTAL 0.30 0.10 0.11 0.10 0.68 0.68 0.72 68.3% Runoff Coeff. Composite Runoff Coefficient The Green Solution - Fort Collins TIME OF CONCENTRATION JOB NO: DATE: 3/17/2016 PROJECT: TGSFCCO01 CALCULATED BY: JAR DESIGN STORM: 2 YEAR INITIAL/OVERLAND TRAVEL TIME FINAL TIME (ti) (tt) tc TRIBUTARY AREA C LENGTH SLOPE ti LENGTH SLOPE Conveyance VEL tt COMP. TOTAL (L/180)+10 BASINS Ac Ft % Min. Ft. % Coefficient fps Min. tc LENGTH Min. Min. (2) (3) (4) (5) (6) (7) (8) (9) (10) (11) (12) (13) (14) A-1 0.06 0.81 14 2.80 1.43 95 1.50 20 2.45 0.65 2.07 109 10.61 5.00 A-2 0.02 0.74 35 2.00 3.15 10 1.00 20 2.00 0.08 3.24 45 10.25 5.00 B-1 0.11 0.95 25 0.50 1.76 16 0.50 20 1.41 0.19 1.95 41 10.23 5.00 B-2 0.03 0.10 6 1.20 4.31 63 1.00 20 2.00 0.53 4.84 69 10.38 5.00 B-3 0.01 0.87 11 2.00 1.14 56 2.50 20 3.16 0.29 1.43 67 10.37 5.00 OS-1 0.06 0.22 17 2.00 5.37 45 2.00 7 0.99 0.76 6.13 62 10.34 5.00 OS-2 0.01 0.95 12 3.50 0.64 0.00 0.00 0.64 12 10.07 5.00 NOTES: Ti = [1.87 x (1.1 - CxC f) x L 0.5 ] / (S 0.33 ) *S IN %* V = (Cv) x (S w 0.5 ) Tt = L / (60 x V) TC Check = 10 + L/180 (Urbanized Basins Only) Tc Min = 5 Minutes (Per UDFCD 2.4.4) tc CHECK (URBANIZED BASINS) The Green Solution - Fort Collins TIME OF CONCENTRATION JOB NO: DATE: 3/17/2016 PROJECT: TGSFCCO01 CALCULATED BY: JAR DESIGN STORM: 100 YEAR INITIAL/OVERLAND TRAVEL TIME FINAL TIME (ti) (tt) tc TRIBUTARY AREA C5 LENGTH SLOPE ti LENGTH SLOPE Conveyance VEL tt COMP. TOTAL (L/180)+10 BASINS Ac Ft % Min. Ft. % Coefficient fps Min. tc LENGTH Min. Min. (2) (3) (4) (5) (6) (7) (8) (9) (10) (11) (12) (13) (14) A-1 0.06 0.86 18 2.80 1.34 47 1.50 20 2.45 0.32 1.66 65 10.36 5.00 A-2 0.02 0.79 18 2.80 1.76 47 1.50 20 2.45 0.32 2.08 65 10.36 5.00 B-1 0.11 1.00 18 2.80 0.56 47 1.50 20 2.45 0.32 0.88 65 10.36 5.00 B-2 0.03 0.13 18 2.80 5.45 47 1.50 20 2.45 0.32 5.77 65 10.36 5.00 B-3 0.01 0.92 18 2.80 1.02 47 1.50 20 2.45 0.32 1.34 65 10.36 5.00 OS-1 0.06 0.25 18 2.80 4.74 47 1.50 20 2.45 0.32 5.05 65 10.36 5.00 OS-2 0.01 1.00 18 2.80 0.56 47 1.50 20 2.45 0.32 0.88 65 10.36 5.00 NOTES: Ti = [1.87 x (1.1 - CxC f) x L 0.5 ] / (S 0.33 ) *S IN %* V = (Cv) x (S w 0.5 ) Tt = L / (60 x V) TC Check = 10 + L/180 (Urbanized Basins Only) Tc Min = 5 Minutes (Per UDFCD 2.4.4) tc CHECK (URBANIZED BASINS) DATE: 3/17/2016 JOB NO: CALCULATED BY: JAR PROJECT: TGSFCCO01 DIRECT RUNOFF TOTAL RUNOFF CARRYOVER Basin Design Area C2 C x A Tc Intensity Qd = CIA C x A Tc Intensity Qd = CIA C x A Tc Intensity Qd = CIA To Design Point (acres) (min) (in/hr) (cfs) (min) (in/hr) (cfs) (min) (in/hr) (cfs) Point A-1 1 0.06 0.81 0.05 5.00 2.88 0.13 A-2 2 0.02 0.74 0.02 5.00 2.88 0.05 A1+A2 0.18 B-1 3 0.11 0.95 0.10 5.00 2.88 0.30 B-2 4 0.03 0.10 0.00 5.00 2.88 0.01 B-3 3 0.01 0.87 0.01 5.00 2.88 0.03 B1+B2+B3 0.35 OS-1 5 0.06 0.22 0.01 5.00 2.88 0.04 OS-2 6 0.01 0.95 0.01 5.00 2.88 0.03 OS1+OS2 0.07 TOTAL 0.59 NOTES: The Green Solution - Fort Collins 2-YEAR RUNOFF CALCULATIONS I values obtained from City of Fort Collins IDF Table DATE: 3/17/2016 JOB NO: CALCULATED BY: JAR PROJECT: TGSFCCO01 DIRECT RUNOFF TOTAL RUNOFF CARRYOVER Basin Design Area C100 C x A Tc Intensity Qd = CIA C x A Tc Intensity Qd = CIA C x A Tc Intensity Qd = CIA To Design Point (acres) (min) (in/hr) (cfs) (min) (in/hr) (cfs) (min) (in/hr) (cfs) Point A-1 1 0.06 0.86 0.05 5.00 9.96 0.48 A-2 2 0.02 0.79 0.02 5.00 9.96 0.18 A1+A2 0.66 B-1 3 0.11 1.00 0.11 5.00 9.96 1.10 B-2 4 0.03 0.13 0.00 5.00 9.96 0.04 B-3 3 0.01 0.92 0.01 5.00 9.96 0.13 B1+B2+B3 1.26 OS-1 5 0.06 0.25 0.01 5.00 9.96 0.14 OS-2 6 0.01 1.00 0.01 5.00 9.96 0.12 OS1+OS2 0.26 TOTAL 2.18 NOTES: The Green Solution - Fort Collins 100-YEAR RUNOFF CALCULATIONS I values obtained from City of Fort Collins IDF Table Appendix C Filterra Design Information Hydraulic Calculations Filterra Sizing - Denver Sizing Basis: Design Parameters: Design Storm = 0.60" Rainfall (WQ Event per Urban Drainage) Filterra Media Flow Rate = 140"/hr Site Drainage Area = 0.585 Percent Impervious = 100% (CN = 98) Time of Concentration = 6 min Allowable Ponding in Filterra = 9" Filterra Model Size Analyzed = 13' x 7' (Treats 0.295 cfs at 140"/hr) Design Summary: Table 1. Filterra Sizing based on the Denver Design Storm. System Size Treatment Flow Rate at 140"/hr Maximum Impervious Drainage Area When Fully Ponded (CN = 98) Outlet Pipe Size (ft) (cfs) (ac) 4x4 0.05 0.102 4" PVC 4x6 / 6x4 0.08 0.154 4" PVC 4x8 / 8x4 0.10 0.205 4" PVC 6x6 0.12 0.231 4" PVC 6x8 / 8x6 / 4x12 / 12x4 0.16 0.308 4" PVC 6x10 / 10x6 0.19 0.386 6" PVC 6x12 / 12x6 0.23 0.463 6" PVC 7x13 / 13x7 0.29 0.585 6" PVC Notes: 3. Dimensions shown are internal. 4. Contact Contech for site specific sizing. The sizing for the Filterra system under the Denver regulations is based on designing the system to provide treatment of the 0.60" design storm. Contech has utilized a SCS Type II - 12 hr storm to model the water quality event. To validate the sizing, the following parameters were assumed: This storm can then be routed through an appropriately sized Filterra unit, in this case a 13x7. Because the Filterra system can provide up to 9" of ponding, some flow attentuation is possible and the Filterra system is able to accommodate a portion of the water quality volume in the head space and release it at the system's design flow rate. The hydrograph in Figure 2 illustrates this concept. In this example, the 68 cf stored represents the upper portion of the hydrograph between 0.29 cfs and 0.47 cfs. 2. A standard PVC pipe coupling is cast into the wall for easy connection to discharge piping This approach is scalable and can be completed for all Filterra sizes. Table 1 identifies the maximum impervious drainage area to each Filterra unit based on this methodology. Addtionally, for drainage areas that are larger, or not fully impervious, Contech can prepare a custom sizing on a project specific basis to provide the most economical system design. Figure 1. Inflow rate during the 0.60" rainfall WQ Storm event. Figure 2. Inflow rate during the WQ Storm Event compared with the Filterra outflow rate, accounting for 9" ponding within the unit. 1. Boxes are standard depth from rim to outlet: 3.5' for Standard Offline, 4.0' for Internal Bypass Curb. Contact Contech for information on Internal Bypass - Pipe systems. Utilizing the HydroCAD Software, a hydrograph can be derived to represent the design storm (Figure 1). Based on Figure 1, the required treatment flow rate for this drainage area is 0.48 cfs. Project Description Solve For Headwater Elevation Input Data Discharge 0.44 ft³/s Centroid Elevation 0.33 ft Tailwater Elevation 0.00 ft Discharge Coefficient 0.60 Opening Width 1.33 ft Opening Height 0.67 ft Results Headwater Elevation 0.34 ft Headwater Height Above Centroid 0.01 ft Tailwater Height Above Centroid -0.33 ft Flow Area 0.89 ft² Velocity 0.49 ft/s Trash Enclosure Wall Opening 2/2/2016 2:02:40 PM Bentley Systems, Inc. Haestad Methods Solution Bentley Center FlowMaster V8i (SELECTseries 1) [08.11.01.03] 27 Siemons Company Drive Suite 200 W Watertown, CT 06795 USA +1-203-755-1666 Page 1 of 1 3130 Verona Avenue • Buford, GA 30518 (866) 888-8479 / (770) 932-2443 • Fax: (770) 932-2490 © Nyloplast Inlet Capacity Charts June 2012 0.00 1.00 2.00 3.00 4.00 5.00 6.00 7.00 8.00 9.00 10.00 11.00 0.00 0.05 0.10 0.15 0.20 0.25 0.30 0.35 0.40 0.45 0.50 0.55 0.60 0.65 0.70 0.75 0.80 0.85 0.90 0.95 1.00 1.05 1.10 Capacity (cfs) Head (ft) Nyloplast 2' x 2' Road & Highway Grate Inlet Capacity Chart Appendix D Geotechnical Report Geotechnical Engineering Report The Green Solution 810 North College Avenue Fort Collins, Colorado April 8, 2016 Terracon Project No. 20165027 Prepared for: Manhard Consulting, Ltd. Centennial, Colorado Prepared by: Terracon Consultants, Inc. Fort Collins, Colorado TABLE OF CONTENTS EXECUTIVE SUMMARY ............................................................................................................ i 1.0 INTRODUCTION .............................................................................................................1 2.0 PROJECT INFORMATION .............................................................................................1 2.1 Project Description ...............................................................................................1 2.2 Site Location and Description...............................................................................2 3.0 SUBSURFACE CONDITIONS ........................................................................................2 3.1 Typical Subsurface Profile ...................................................................................2 3.2 Laboratory Testing ...............................................................................................2 3.3 Corrosion Protection (Water-Soluble Sulfates) .....................................................2 3.4 Groundwater ........................................................................................................3 3.5 Percolation Test Results ......................................................................................3 4.0 RECOMMENDATIONS FOR DESIGN AND CONSTRUCTION ......................................4 4.1 Geotechnical Considerations ...............................................................................4 4.1.1 Existing, Undocumented Fill .....................................................................4 4.1.2 Groundwater .............................................................................................4 4.1.3 Foundation Recommendations .................................................................4 4.2 Earthwork.............................................................................................................4 4.2.1 Site Preparation ........................................................................................4 4.2.2 Excavation ................................................................................................5 4.2.3 Subgrade Preparation ...............................................................................5 4.2.4 Fill Materials and Placement ......................................................................6 4.2.5 Compaction Requirements ........................................................................7 4.2.6 Utility Trench Backfill ................................................................................7 4.3 Seismic Considerations........................................................................................7 4.4 Lateral Earth Pressures .......................................................................................8 5.0 GENERAL COMMENTS .................................................................................................9 TABLE OF CONTENTS (continued) Appendix A – FIELD EXPLORATION Exhibit A-1 Site Location Map Exhibit A-2 Exploration Plan Exhibit A-3 Field Exploration Description Exhibit A-4 Boring Log Appendix B – LABORATORY TESTING Exhibit B-1 Laboratory Testing Description Exhibit B-2 Atterberg Limits Test Results Exhibit B-3 Grain-size Distribution Test Results Exhibit B-4 Water-Soluble Sulfate Test Results Appendix C – SUPPORTING DOCUMENTS Exhibit C-1 General Notes Exhibit C-2 Unified Soil Classification System Exhibit C-3 Description of Rock Properties Exhibit C-4 Laboratory Test Significance and Purpose Exhibits C-5 and C-6 Report Terminology Geotechnical Engineering Report The Green Solution ■ Fort Collins, Colorado April 8, 2016 ■ Terracon Project No. 20165027 Responsive ■ Resourceful ■ Reliable i EXECUTIVE SUMMARY A geotechnical investigation has been performed for the proposed dry well placed at The Green Solution to be constructed at 810 North College Avenue in Fort Collins, Colorado. One (1) boring, presented as Exhibit A-4 and designated as Boring No. 1, was performed to a depth of approximately 24.4 feet below existing site grades. In addition, a single percolation test in the upper soils was performed in a separate boring. This report specifically addresses the recommendations for the proposed Limited Impact Development (LID). Detailed recommendations for the design of a drywell infiltration feature are outside our scope of work. The boring performed in this area is for informational purposes and will be utilized by others. Based on the information obtained from our subsurface exploration, the site can be developed for the proposed project. However, the following geotechnical considerations were identified and will need to be considered: Existing, undocumented fill was encountered in the boring performed at this site to an approximate depth of 4 feet below existing site grades. The existing fill soils should be removed and replaced with engineered fill beneath the proposed dry well structure. Very loose clayey sand soils were encountered at anticipated dry well bearing depths. We believe subgrade stabilization will be required prior to placement of the dry well to reduce risk for unacceptable movements. Recommendations for subgrade stabilization alternatives are presented in the report. Groundwater was encountered in the boring completed at a depth of about 8.2 feet below existing site grades when checked several days after drilling. Groundwater levels can and should be expected to fluctuate with varying seasonal and weather conditions, irrigation demands on or adjacent to the site and with fluctuations in nearby water features. Depending on depths of the proposed dry well and associated utilizes, groundwater may impact the proposed construction. Terracon assumes the proposed dry well will be a precast or pre-manufactured structure. On-site soils or imported fill can be used for construction provided the recommendations discussed in the 4.2 Earthwork section of this report are followed. Percolation testing was performed in a borehole completed in the southwest portion of the property. Based on field test results, we recommend using a percolation rate 6 minutes per inch when planning for any infiltration of LID improvements on the project site. The 2012 International Building Code, Table 1613.5.2 IBC seismic site classification for this site is D. Geotechnical Engineering Report The Green Solution ■ Fort Collins, Colorado April 8, 2016 ■ Terracon Project No. 20165027 Responsive ■ Resourceful ■ Reliable ii Close monitoring of the construction operations discussed herein will be critical in achieving the design subgrade support. We therefore recommend that Terracon be retained to monitor this portion of the work. This summary should be used in conjunction with the entire report for design purposes. It should be recognized that details were not included or fully developed in this section, and the report must be read in its entirety for a comprehensive understanding of the items contained herein. The section titled GENERAL COMMENTS should be read for an understanding of the report limitations. Responsive ■ Resourceful ■ Reliable 1 GEOTECHNICAL ENGINEERING REPORT The Green Solution 810 North College Avenue Fort Collins, Colorado Terracon Project No. 20165027 April 8, 2016 1.0 INTRODUCTION This report presents the results of our geotechnical engineering services performed for the proposed dry well planned at The Green Solution to be located at 810 North College Avenue in Fort Collins, Colorado (Exhibit A-1). The purpose of these services is to provide information and geotechnical engineering recommendations relative to: subsurface soil and bedrock conditions percolation rates groundwater conditions earthwork lateral earth pressures seismic considerations dry well design and construction Our geotechnical engineering scope of work for this project included the advancement of a single test boring to a depth ranging from approximately 25 feet below existing site grade, a percolation test boring and performing a percolation test, laboratory testing for soil engineering properties and engineering analyses to provide design and construction recommendations for the proposed dry well. A Log of the boring along with an Exploration Plan (Exhibit A-2) are included in Appendix A. The results of the laboratory testing performed on soil and bedrock samples obtained from the site during the field exploration are included in Appendix B. 2.0 PROJECT INFORMATION 2.1 Project Description Item Description Site layout Refer to the Exploration Plan (Exhibit A-2 in Appendix A) Proposed construction We understand a building addition is planned requiring some LID design considerations. The LID design concept will likely include a dry well or similar type solution to likely be constructed in the southwestern portion of the property. Geotechnical Engineering Report The Green Solution ■ Fort Collins, Colorado April 8, 2016 ■ Terracon Project No. 20165027 Responsive ■ Resourceful ■ Reliable 2 2.2 Site Location and Description Item Description Location The project site is located at 810 North College Avenue in Fort Collins, Colorado. Existing improvements The site is occupied by an existing single-story building with retail development surrounding the site. Current ground cover The ground surface is covered with asphalt, gravel-surfaced or bare ground. A landscaped bed is located in the southwest portion of the property covered with topsoil and landscaped mulch. Existing topography The site appears relatively flat. 3.0 SUBSURFACE CONDITIONS 3.1 Typical Subsurface Profile Specific conditions encountered at the boring location are indicated on the boring log included in Appendix A. Stratification boundaries on the boring log represent the approximate location of changes in soil types; in-situ, the transition between materials may be gradual. Based on the results of the boring, subsurface conditions on the project site can be generalized as follows: Material Description Approximate Depth to Bottom of Stratum (feet) Consistency/Density/Hardness Fill materials consisting of clayey sand About 4 feet below existing site grade. -- Clayey sand About 8.5 feet below existing site grade. Very loose Sand with silt and gravel About 12 to 15 feet below existing site grade. Medium dense to very dense Sandstone bedrock To the maximum depth of exploration of about 24.2 feet. Very hard 3.2 Laboratory Testing A sample of site soil selected for plasticity testing exhibited moderate plasticity with a liquid limit ranging of 39 and plasticity index of 17. Laboratory test results are presented in Appendix B. 3.3 Corrosion Protection (Water-Soluble Sulfates) Results of water-soluble sulfate testing indicate that ASTM Type I or II portland cement should be specified for all project concrete on and below grade. Dry well concrete should be designed for Geotechnical Engineering Report The Green Solution ■ Fort Collins, Colorado April 8, 2016 ■ Terracon Project No. 20165027 Responsive ■ Resourceful ■ Reliable 3 low sulfate exposure in accordance with the provisions of the ACI Design Manual, Section 318, Chapter 4. 3.4 Groundwater The borehole was observed while drilling and after completion for the presence and level of groundwater. In addition, a delayed water level was also obtained in the boring. The water level observed in the borehole is noted on the attached boring log, and are summarized below: Boring Number Depth to groundwater while drilling, ft. Depth to groundwater 2 days after drilling, ft. Elevation of groundwater 8 days after drilling, ft. 1 8.5 8.2 4,960.5 These observations represent groundwater conditions at the time of the field exploration, and may not be indicative of other times or at other locations. Groundwater levels can be expected to fluctuate with varying seasonal and weather conditions, and other factors. Groundwater level fluctuations occur due to seasonal variations in the water levels present in the Cache la Poudre River, amount of rainfall, runoff and other factors not evident at the time the boring was performed. Therefore, groundwater levels during construction or at other times in the life of the structure may be higher or lower than the levels indicated on the boring log. The possibility of groundwater level fluctuations should be considered when developing the design and construction plans for the project. 3.5 Percolation Test Results A single percolation testing conducted near the area of the proposed drywell is summarized as follows: Percolation Test Results Test Hole Depth (inches) Soil Classification Percolation Rate (minutes/inch) Percolation Hole 35 Poorly graded sand, with gravel and silt 6 Percolation rates of approximately 4.2 to 8.3 minutes per inch were obtained from testing conducted in the percolation test hole. Typically, the minimum infiltration rate (slowest) is used to design subsurface infiltration elements. However, based on the field test results and our experience in the area, we recommend utilizing a percolation rate of 6 minutes per inch when planning for any infiltration of LID improvements on the project site. Geotechnical Engineering Report The Green Solution ■ Fort Collins, Colorado April 8, 2016 ■ Terracon Project No. 20165027 Responsive ■ Resourceful ■ Reliable 4 4.0 RECOMMENDATIONS FOR DESIGN AND CONSTRUCTION 4.1 Geotechnical Considerations Based on subsurface conditions encountered in the boring, the site appears suitable for the proposed construction from a geotechnical point of view provided certain precautions and design and construction recommendations described in this report are followed. We have identified geotechnical conditions that could impact design and construction of the proposed dry well. 4.1.1 Existing, Undocumented Fill As previously noted, existing undocumented fill was encountered to a depth of about 4 feet in the boring drilled at the site. We do not possess any information regarding whether the fill was placed under the observation of a geotechnical engineer. The existing fill soils should be removed and replaced with engineered fill beneath the proposed dry well structure. 4.1.2 Groundwater As previously stated, groundwater was measured at a depth of 8.2 feet below existing site grades. Terracon recommends maintaining a separation of at least 3 feet between the bottom of proposed dry well and measured groundwater levels. It is also possible and likely that groundwater levels below this site may rise as water levels in the Cache la Poudre River rise. 4.1.3 Foundation Recommendations Terracon assumes the proposed dry well will be a precast or pre-manufactured structure. On-site soils or imported fill can be used for construction provided the recommendations discussed in the 4.2 Earthwork section of this report are followed. 4.2 Earthwork The following presents recommendations for site preparation, excavation, subgrade preparation and placement of engineered fills on the project. All earthwork on the project should be observed and evaluated by Terracon on a full-time basis. The evaluation of earthwork should include observation of over-excavation operations, testing of engineered fills, subgrade preparation, subgrade stabilization, and other geotechnical conditions exposed during the construction of the project. 4.2.1 Site Preparation Prior to placing any fill, strip and remove existing vegetation and undocumented existing fill below the dry well, and any other deleterious materials from the proposed construction areas. Stripped organic materials, if present, should be wasted from the site or used to re-vegetate landscaped areas after completion of grading operations. Prior to the placement of fills, the site Geotechnical Engineering Report The Green Solution ■ Fort Collins, Colorado April 8, 2016 ■ Terracon Project No. 20165027 Responsive ■ Resourceful ■ Reliable 5 should be graded to create a relatively level surface to receive fill, and to provide for a relatively uniform thickness of fill beneath proposed pre-cast structure. 4.2.2 Excavation It is anticipated that excavations for the proposed construction can be accomplished with conventional earthmoving equipment. Excavations into the on-site soils will encounter very loose soil conditions with possible caving conditions. The soils to be excavated can vary significantly across the site as their classifications are based solely on the materials encountered in widely-spaced exploratory test borings. The contractor should verify that similar conditions exist throughout the proposed area of excavation. If different subsurface conditions are encountered at the time of construction, the actual conditions should be evaluated to determine any excavation modifications necessary to maintain safe conditions. Although evidence of underground facilities such as septic tanks, vaults, basements, and utilities was not observed during the site reconnaissance, such features could be encountered during construction. If underground facilities are encountered, such features should be removed and the excavation thoroughly cleaned prior to backfill placement and/or construction. Any over-excavation that extends below the bottom of the dry well should extend laterally beyond all edges of the dry well footprint at least 8 inches per foot of over-excavation depth below the dry well. The over-excavation should be backfilled to the dry well bearing elevation in accordance with the recommendations presented in this report. Depending upon depth of excavation and seasonal conditions, surface water infiltration and/or groundwater may be encountered in excavations on the site. It is anticipated that pumping from sumps may be utilized to control water within excavations. The subgrade soil conditions should be evaluated during the excavation process and the stability of the soils determined at that time by the contractors’ Competent Person. Slope inclinations flatter than the OSHA maximum values may have to be used. The individual contractor(s) should be made responsible for designing and constructing stable, temporary excavations as required to maintain stability of both the excavation sides and bottom. All excavations should be sloped or shored in the interest of safety following local, and federal regulations, including current OSHA excavation and trench safety standards. As a safety measure, it is recommended that all vehicles and soil piles be kept a minimum lateral distance from the crest of the slope equal to the slope height. The exposed slope face should be protected against the elements 4.2.3 Subgrade Preparation After the undocumented existing fill has been removed from the construction area, the top 8 inches of the exposed ground surface should be scarified, moisture conditioned, and recompacted Geotechnical Engineering Report The Green Solution ■ Fort Collins, Colorado April 8, 2016 ■ Terracon Project No. 20165027 Responsive ■ Resourceful ■ Reliable 6 to at least 95 percent of the maximum dry unit weight as determined by ASTM D698 before any new fill is placed. If pockets of soft, loose, or otherwise unsuitable materials are encountered at the bottom of the excavations, the proposed dry well bearing elevations may be reestablished by over-excavating the unsuitable soils and backfilling with compacted engineered fill or lean concrete. After the bottom of the excavation has been compacted, engineered fill can be placed to bring the subgrade to the desired grade. Engineered fill should be placed in accordance with the recommendations presented in subsequent sections of this report. The stability of the subgrade may be affected by precipitation, repetitive construction traffic or other factors. If unstable conditions develop, workability may be improved by scarifying and drying. Alternatively, over-excavation of wet zones and replacement with granular materials may be used, or crushed gravel and/or rock can be tracked or “crowded” into the unstable surface soil until a stable working surface is attained. 4.2.4 Fill Materials and Placement The on-site soils or approved granular and low plasticity cohesive imported materials may be used as fill material. The soil removed from this site that is free of organic or objectionable materials, as defined by a field technician who is qualified in soil material identification and compaction procedures, can be re-used as fill. It should be noted that on-site materials may require reworking to adjust the moisture content to meet the compaction criteria. Imported soils (if required) should meet the following material property requirements: Gradation Percent finer by weight (ASTM C136) 4” 100 3” 70-100 No. 4 Sieve 50-100 No. 200 Sieve 5-15 Soil Properties Value Liquid Limit 30 (max.) Plastic Limit 15 (max.) Maximum Expansive Potential (%) Non-expansive1 1. Measured on a sample compacted to approximately 95 percent of the maximum dry unit weight as determined by ASTM D698 at optimum moisture content. The sample is confined under a 100 psf surcharge and submerged. Geotechnical Engineering Report The Green Solution ■ Fort Collins, Colorado April 8, 2016 ■ Terracon Project No. 20165027 Responsive ■ Resourceful ■ Reliable 7 4.2.5 Compaction Requirements Engineered fill should be placed and compacted in horizontal lifts, using equipment and procedures that will produce recommended moisture contents and densities throughout the lift. Item Description Fill lift Thickness 9 inches or less in loose thickness when heavy, self- propelled compaction equipment is used 4 to 6 inches in loose thickness when hand-guided equipment (i.e. jumping jack or plate compactor) is used Minimum compaction requirements 95 percent of the maximum dry unit weight as determined by ASTM D 698. Moisture content cohesive soil (clay) -1 to +3 % of the optimum moisture content Moisture content cohesionless soil (sand) -2 to +2 % of the optimum moisture content 1. We recommend engineered fill be tested for moisture content and compaction during placement. Should the results of the in-place density tests indicate the specified moisture or compaction limits have not been met, the area represented by the test should be reworked and retested as required until the specified moisture and compaction requirements are achieved. 2. Specifically, moisture levels should be maintained low enough to allow for satisfactory compaction to be achieved without the fill material pumping when proofrolled. 3. Moisture conditioned clay materials should not be allowed to dry out. A loss of moisture within these materials could result in an increase in the material’s expansive potential. Subsequent wetting of these materials could result in undesirable movement. 4.2.6 Utility Trench Backfill All trench excavations should be made with sufficient working space to permit construction including backfill placement and compaction. All underground piping within or near the proposed structure should be designed with flexible couplings, so minor deviations in alignment do not result in breakage or distress. It is imperative that utility trenches be properly backfilled with relatively clean materials. If utility trenches are backfilled with relatively clean granular material, they should be capped with at least 18 inches of cohesive fill in non-pavement areas to reduce the infiltration and conveyance of surface water through the trench backfill. It is strongly recommended that a representative of Terracon provide full-time observation and compaction testing of fill within the construction area. 4.3 Seismic Considerations Code Used Site Classification 2012 International Building Code (IBC) 1 D 2 Geotechnical Engineering Report The Green Solution ■ Fort Collins, Colorado April 8, 2016 ■ Terracon Project No. 20165027 Responsive ■ Resourceful ■ Reliable 8 Code Used Site Classification 1. In general accordance with the 2012 International Building Code, Table 1613.5.2. 2. The 2012 International Building Code (IBC) requires a site soil profile determination extending a depth of 100 feet for seismic site classification. The current scope requested does not include the required 100 foot soil profile determination. The borings completed for this project extended to a maximum depth of about 24½ feet and this seismic site class definition considers that similar soil and bedrock conditions exist below the maximum depth of the subsurface exploration. Additional exploration to deeper depths could be performed to confirm the conditions below the current depth of exploration. Alternatively, a geophysical exploration could be utilized in order to attempt to justify a more favorable seismic site class. 4.4 Lateral Earth Pressures Buried dry well walls with unbalanced backfill levels on opposite sides should be designed for earth pressures at least equal to those indicated in the following table. Earth pressures will be influenced by structural design of the walls, conditions of wall restraint, methods of construction and/or compaction and the strength of the materials being restrained. Two wall restraint conditions are shown. Active earth pressure is commonly used for design of free-standing cantilever retaining walls and assumes wall movement. The "at-rest" condition assumes no wall movement. The recommended design lateral earth pressures do not include a factor of safety and do not provide for possible hydrostatic pressure on the walls. Geotechnical Engineering Report The Green Solution ■ Fort Collins, Colorado April 8, 2016 ■ Terracon Project No. 20165027 Responsive ■ Resourceful ■ Reliable 9 EARTH PRESSURE COEFFICIENTS Earth Pressure Conditions Coefficient for Backfill Type Equivalent Fluid Density (pcf) Surcharge Pressure, p1 (psf) Earth Pressure, p2 (psf) Active (Ka) Imported Fill - 0.27 Clayey sand - 0.33 35 40 (0.27)S (0.33)S (35)H (40)H At-Rest (Ko) Imported Fill - 0.43 Clayey sand - 0.5 56 60 (0.43)S (0.5)S (56)H (60)H Passive (Kp) Imported Fill - 3.69 Clayey sand – 3.00 480 360 --- --- --- --- Applicable conditions to the above include: For active earth pressure, wall must rotate about base, with top lateral movements of about 0.002 H to 0.004 H, where H is wall height; For passive earth pressure to develop, wall must move horizontally to mobilize resistance; Uniform surcharge, where S is surcharge pressure; In-situ soil backfill weight a maximum of 120 pcf; Horizontal backfill, compacted between 95 and 98 percent of maximum dry unit weight as determined by ASTM D698; Loading from heavy compaction equipment not included; No hydrostatic pressures acting on wall; No dynamic loading; No safety factor included in soil parameters; and Ignore passive pressure in frost zone. 5.0 GENERAL COMMENTS Terracon should be retained to review the final design plans and specifications so comments can be made regarding interpretation and implementation of our geotechnical recommendations in Geotechnical Engineering Report The Green Solution ■ Fort Collins, Colorado April 8, 2016 ■ Terracon Project No. 20165027 Responsive ■ Resourceful ■ Reliable 10 or prevention of pollutants, hazardous materials or conditions. If the owner is concerned about the potential for such contamination or pollution, other studies should be undertaken. This report has been prepared for the exclusive use of our client for specific application to the project discussed and has been prepared in accordance with generally accepted geotechnical engineering practices. No warranties, either express or implied, are intended or made. Site safety, excavation support, and dewatering requirements are the responsibility of others. In the event that changes in the nature, design, or location of the project as described in this report are planned, the conclusions and recommendations contained in this report shall not be considered valid unless Terracon reviews the changes and either verifies or modifies the conclusions of this report in writing. APPENDIX A FIELD EXPLORATION TOPOGRAPHIC MAP IMAGE COURTESY OF THE U.S. GEOLOGICAL SURVEY QUADRANGLES INCLUDE: FORT COLLINS, CO (1984). 1901 Sharp Point Dr Ste C Fort Collins, CO 80525-4429 Project Manager: Drawn by: 20165027 KFS Checked by: EDB EDB Approved by: SITE LOCATION MAP 4/6/16 The Green Solution 810 North College Avenue Fort Collins, CO DIAGRAM IS FOR GENERAL LOCATION ONLY, AND IS NOT INTENDED FOR CONSTRUCTION PURPOSES EDB A-1 Project No. Exhibit File Name: Date: Scale: 1”=2,000’ EXPLORATION PLAN 1901 Sharp Point Dr Ste C Fort Collins, CO 80525-4429 AERIAL PHOTOGRAPHY PROVIDED BY 20165027 MICROSOFT BING MAPS The Green Solution 810 North College Avenue Fort Collins, CO DIAGRAM IS FOR GENERAL LOCATION ONLY, AND IS NOT INTENDED FOR CONSTRUCTION PURPOSES EDB 4/6/16 KFS EDB Project Manager: 1 Percolation Test Drawn by: Checked by: Approved by: EDB Scale: Project No. File Name: Date: AS SHOWN A-2 Exhibit Geotechnical Engineering Report The Green Solution ■ Fort Collins, Colorado April 8, 2016 ■ Terracon Project No. 20165027 Responsive ■ Resourceful ■ Reliable Exhibit A-3 Field Exploration Description The boring location was based upon proposed development shown on a provided site plan. The boring was located in the field by measuring from property lines and existing site features. The ground surface elevation was surveyed using an engineer’s level at the boring location referencing a City of Fort Collins benchmark (1-00) located at the southeast corner of North College Avenue and East Vine Street (elevation 4968.74). The boring was drilled with a CME-75 truck-mounted rotary drill rig with solid-stem augers. During the drilling operations, a lithologic log of the boring was recorded by the field engineer. Disturbed samples were obtained at selected intervals utilizing a 2-inch outside diameter split-spoon sampler. Penetration resistance values were recorded in a manner similar to the standard penetration test (SPT). This test consists of driving the sampler into the ground with a 140-pound hammer free-falling through a distance of 30 inches. The number of blows required to advance the split-spoon sample 18 inches (final 12 inches are recorded) or the interval indicated, is recorded as a standard penetration resistance value (N-value). The blow count values are indicated on the boring log at the respective sample depths. A CME automatic SPT hammer was used to advance the samplers in the boring performed on this site. A greater efficiency is typically achieved with the automatic hammer compared to the conventional safety hammer operated with a cathead and rope. Published correlations between the SPT values and soil properties are based on the lower efficiency cathead and rope method. This higher efficiency affects the standard penetration resistance blow count value by increasing the penetration per hammer blow over what would be obtained using the cathead and rope method. The effect of the automatic hammer's efficiency has been considered in the interpretation and analysis of the subsurface information for this report. The standard penetration test provides a reasonable indication of the in-place density of sandy type materials, but only provides an indication of the relative stiffness of cohesive materials since the blow count in these soils may be affected by the moisture content of the soil. In addition, considerable care should be exercised in interpreting the N-values in gravelly soils, particularly where the size of the gravel particle exceeds the inside diameter of the sampler. Groundwater measurements were obtained in the boring at the time of site exploration and several days after drilling. After subsequent groundwater measurements were obtained, the boring was backfilled with auger cuttings and sand (if needed). Some settlement of the backfill may occur and should be repaired as soon as possible. 49 5 25 21 13 14 19 39-22-17 NP 4964.5 4960 4946.5 4944.5 0-1-1 N=2 2-8-16 N=24 20-40-45 N=85 12-25-30 N=55 50/5" 4.0 8.5 22.0 24.4 FILL - CLAYEY SAND (SC), fine grained, dark brown to brown CLAYEY SAND (SC), fine grained, dark brown to brown, very loose POORLY GRADED SAND WITH SILT AND GRAVEL (SP-SM), fine to coarse grained, yellowish-brown to light brown, medium dense to very dense, subrounded to subangular SEDIMENTARY BEDROCK - SANDSTONE, fine grained, gray to light gray, very hard, with thin seams of black, organic materials Boring Terminated at 24.4 Feet Stratification lines are approximate. In-situ, the transition may be gradual. Hammer Type: Automatic GRAPHIC LOG THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL 20165027.GPJ TERRACON2015.GDT 4/8/16 810 North College Avenue Fort Collins, Colorado SITE: Page 1 of 1 Advancement Method: 4-inch Continuous Flight Auger Abandonment Method: Borings backfilled with soil cuttings upon completion. 1901 Sharp Point Dr Ste C Fort Collins, CO Notes: Project No.: 20165027 Drill Rig: CME-75 Boring Started: 3/28/2016 BORING LOG NO. 1 CLIENT: Manhard Consulting, Ltd. Centennial, Colorado Driller: S.Flannigan Boring Completed: 3/28/2016 See Exhibit A-3 for description of field procedures. See Appendix B for description of laboratory procedures and additional data (if any). See Appendix C for explanation of symbols and APPENDIX B LABORATORY TESTING Responsive ■ Resourceful ■ Reliable Exhibit B-1 Laboratory Testing Description The soil and bedrock samples retrieved during the field exploration were returned to the laboratory for observation by the project geotechnical engineer. At that time, the field descriptions were reviewed and an applicable laboratory testing program was formulated to determine engineering properties of the subsurface materials. Laboratory tests were conducted on selected soil and bedrock samples. The results of these tests are presented on the boring log and in this appendix. The test results were used for the geotechnical engineering analyses, and the development of subgrade preparation and earthwork recommendations. The laboratory tests were performed in general accordance with applicable locally accepted standards. Soil samples were classified in general accordance with the Unified Soil Classification System described in Appendix C. Rock samples were visually classified in general accordance with the description of rock properties presented in Appendix C. Procedural standards noted in this report are for reference to methodology in general. In some cases variations to methods are applied as a result of local practice or professional judgment. Water content Plasticity index Grain-size distribution Water-soluble sulfate content Geotechnical Engineering Report The Green Solution ■ Fort Collins, Colorado April 8, 2016 ■ Terracon Project No. 20165027 0 10 20 30 40 50 60 0 20 40 60 80 100 CL or OL CH or OH ML or OL MH or OH Boring ID Depth PL PI Description SC CLAYEY SAND Fines P L A S T I C I T Y I N D E X LIQUID LIMIT "U" Line "A" Line 39 22 17 49 LL USCS 1 ATTERBERG LIMITS RESULTS ASTM D4318 4 - 5.5 PROJECT NUMBER: 20165027 PROJECT: The Green Solution SITE: 810 North College Avenue Fort Collins, Colorado CLIENT: Manhard Consulting, Ltd. Centennial, Colorado EXHIBIT: B-2 1901 Sharp Point Dr Ste C Fort Collins, CO LABORATORY TESTS ARE NOT VALID IF SEPARATED FROM ORIGINAL REPORT. ATTERBERG LIMITS 20165027.GPJ TERRACON2015.GDT 4/1/16 CL-ML 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 100 10 1 0.1 0.01 0.001 1 1 39 NP 0.801 0.115 4.206 19 25 6 16 20 30 40 50 1.5 6 200 810 9.5 0.206 38.0 14 49.0 5.4 %Fines LL PL PI 1 4 3/4 1/2 60 fine 1 1 20.39 GRAIN SIZE IN MILLIMETERS PERCENT FINER BY WEIGHT coarse fine U.HYDROMETERS. SIEVE OPENING IN INCHES U.S. SIEVE NUMBERS 22 NP 17 NP 0.74 D100 Cc Cu TASK NO: 160331031 Analytical Results Terracon, Inc. - Fort Collins Eric D. Bernhardt Company: Report To: Company: Bill To: 1901 Sharp Point Drive Suite C Fort Collins CO 80525 Accounts Payable Terracon, Inc. - Lenexa 13910 W. 96th Terrace Lenexa KS 66215 20165027 Date Reported: 4/7/16 Task No.: 160331031 Matrix: Soil - Geotech Date Received: 3/31/16 Client Project: Client PO: Customer Sample ID 20165027 BH1 4 Ft. Test Method Lab Number: 160331031-01 Result Sulfate - Water Soluble 0.035 % AASHTO T290-91/ ASTM D4327 240 South Main Street / Brighton, CO 80601-0507 / 303-659-2313 Mailing Address: P.O. Box 507 / Brighton, CO 80601-0507 / Fax: 303-659-2315 DATA APPROVED FOR RELEASE BY Abbreviations/ References: 160331031 AASHTO - American Association of State Highway and Transportation Officials. ASTM - American Society for Testing and Materials. ASA - American Society of Agronomy. DIPRA - Ductile Iron Pipe Research Association Handbook of Ductile Iron Pipe. APPENDIX C SUPPORTING DOCUMENTS Exhibit: C-1 Unconfined Compressive Strength Qu, (psi) 3.5 to 7.0 14.0 to 28.0 28.0 to 55.5 7.0 to 14.0 less than 3.50 > 55.5 Non-plastic Low Medium High DESCRIPTION OF SYMBOLS AND ABBREVIATIONS SAMPLING WATER LEVEL FIELD TESTS GENERAL NOTES Over 12 in. (300 mm) 12 in. to 3 in. (300mm to 75mm) 3 in. to #4 sieve (75mm to 4.75 mm) #4 to #200 sieve (4.75mm to 0.075mm Passing #200 sieve (0.075mm) Particle Size < 5 5 - 12 > 12 Percent of Dry Weight Descriptive Term(s) of other constituents RELATIVE PROPORTIONS OF FINES 0 1 - 10 11 - 30 > 30 Plasticity Index Soil classification is based on the Unified Soil Classification System. Coarse Grained Soils have more than 50% of their dry weight retained on a #200 sieve; their principal descriptors are: boulders, cobbles, gravel or sand. Fine Grained Soils have less than 50% of their dry weight retained on a #200 sieve; they are principally described as clays if they are plastic, and silts if they are slightly plastic or non-plastic. Major constituents may be added as modifiers and minor constituents may be added according to the relative proportions based on grain size. In addition to gradation, coarse-grained soils are defined on the basis of their in-place relative density and fine-grained soils on the basis of their consistency. LOCATION AND ELEVATION NOTES Percent of Dry Weight Major Component of Sample Trace With Modifier RELATIVE PROPORTIONS OF SAND AND GRAVEL GRAIN SIZE TERMINOLOGY Trace With Modifier DESCRIPTIVE SOIL CLASSIFICATION Boulders Cobbles Gravel Sand UNIFIED SOIL CLASSIFICATION SYSTEM Exhibit C-2 Criteria for Assigning Group Symbols and Group Names Using Laboratory Tests A Soil Classification Group Symbol Group Name B Coarse Grained Soils: More than 50% retained on No. 200 sieve Gravels: More than 50% of coarse fraction retained on No. 4 sieve Clean Gravels: Less than 5% fines C Cu 4 and 1 Cc 3 E GW Well-graded gravel F Cu 4 and/or 1 Cc 3 E GP Poorly graded gravel F Gravels with Fines: More than 12% fines C Fines classify as ML or MH GM Silty gravel F,G,H Fines classify as CL or CH GC Clayey gravel F,G,H Sands: 50% or more of coarse fraction passes No. 4 sieve Clean Sands: Less than 5% fines D Cu 6 and 1 Cc 3 E SW Well-graded sand I Cu 6 and/or 1 Cc 3 E SP Poorly graded sand I Sands with Fines: More than 12% fines D Fines classify as ML or MH SM Silty sand G,H,I Fines classify as CL or CH SC Clayey sand G,H,I Fine-Grained Soils: 50% or more passes the No. 200 sieve Silts and Clays: Liquid limit less than 50 Inorganic: PI 7 and plots on or above “A” line J CL Lean clay K,L,M PI 4 or plots below “A” line J ML Silt K,L,M Organic: Liquid limit - oven dried 0.75 OL Organic clay K,L,M,N Liquid limit - not dried Organic silt K,L,M,O Silts and Clays: Liquid limit 50 or more Inorganic: PI plots on or above “A” line CH Fat clay K,L,M PI plots below “A” line MH Elastic Silt K,L,M Organic: Liquid limit - oven dried 0.75 OH Organic clay K,L,M,P Liquid limit - not dried Organic silt K,L,M,Q Highly organic soils: Primarily organic matter, dark in color, and organic odor PT Peat A Based on the material passing the 3-inch (75-mm) sieve B If field sample contained cobbles or boulders, or both, add “with cobbles or boulders, or both” to group name. DESCRIPTION OF ROCK PROPERTIES Exhibit C-3 WEATHERING Fresh Rock fresh, crystals bright, few joints may show slight staining. Rock rings under hammer if crystalline. Very slight Rock generally fresh, joints stained, some joints may show thin clay coatings, crystals in broken face show bright. Rock rings under hammer if crystalline. Slight Rock generally fresh, joints stained, and discoloration extends into rock up to 1 in. Joints may contain clay. In granitoid rocks some occasional feldspar crystals are dull and discolored. Crystalline rocks ring under hammer. Moderate Significant portions of rock show discoloration and weathering effects. In granitoid rocks, most feldspars are dull and discolored; some show clayey. Rock has dull sound under hammer and shows significant loss of strength as compared with fresh rock. Moderately severe All rock except quartz discolored or stained. In granitoid rocks, all feldspars dull and discolored and majority show kaolinization. Rock shows severe loss of strength and can be excavated with geologist’s pick. Severe All rock except quartz discolored or stained. Rock “fabric” clear and evident, but reduced in strength to strong soil. In granitoid rocks, all feldspars kaolinized to some extent. Some fragments of strong rock usually left. Very severe All rock except quartz discolored or stained. Rock “fabric” discernible, but mass effectively reduced to “soil” with only fragments of strong rock remaining. Complete Rock reduced to ”soil”. Rock “fabric” not discernible or discernible only in small, scattered locations. Quartz may be present as dikes or stringers. HARDNESS (for engineering description of rock – not to be confused with Moh’s scale for minerals) Very hard Cannot be scratched with knife or sharp pick. Breaking of hand specimens requires several hard blows of geologist’s pick. Hard Can be scratched with knife or pick only with difficulty. Hard blow of hammer required to detach hand specimen. Moderately hard Can be scratched with knife or pick. Gouges or grooves to ¼ in. deep can be excavated by hard blow of point of a geologist’s pick. Hand specimens can be detached by moderate blow. Medium Can be grooved or gouged 1/16 in. deep by firm pressure on knife or pick point. Can be excavated in small chips to pieces about 1-in. maximum size by hard blows of the point of a geologist’s pick. Soft Can be gouged or grooved readily with knife or pick point. Can be excavated in chips to pieces several inches in size by moderate blows of a pick point. Small thin pieces can be broken by finger pressure. Very soft Can be carved with knife. Can be excavated readily with point of pick. Pieces 1-in. or more in thickness can be broken with finger pressure. Can be scratched readily by fingernail. Joint, Bedding, and Foliation Spacing in Rock a Spacing Joints Bedding/Foliation Less than 2 in. Very close Very thin 2 in. – 1 ft. Close Thin 1 ft. – 3 ft. Moderately close Medium 3 ft. – 10 ft. Wide Thick More than 10 ft. Very wide Very thick a. Spacing refers to the distance normal to the planes, of the described feature, which are parallel to each other or nearly so. Rock Quality Designator (RQD) a Joint Openness Descriptors RQD, as a percentage Diagnostic description Openness Descriptor Exceeding 90 Excellent No Visible Separation Tight 90 – 75 Good Less than 1/32 in. Slightly Open 75 – 50 Fair 1/32 to 1/8 in. Moderately Open 50 – 25 Poor 1/8 to 3/8 in. Open Less than 25 Very poor 3/8 in. to 0.1 ft. Moderately Wide a. RQD (given as a percentage) = length of core in pieces Greater than 0.1 ft. Wide 4 in. and longer/length of run. References: American Society of Civil Engineers. Manuals and Reports on Engineering Practice - No. 56. Subsurface Investigation for Design and Construction of Foundations of Buildings. New York: American Society of Civil Engineers, 1976. U.S. Department of the Interior, Bureau of Reclamation, Engineering Geology Field Manual. Exhibit C-4 LABORATORY TEST SIGNIFICANCE AND PURPOSE Test Significance Purpose California Bearing Ratio Used to evaluate the potential strength of subgrade soil, subbase, and base course material, including recycled materials for use in road and airfield pavements. Pavement Thickness Design Consolidation Used to develop an estimate of both the rate and amount of both differential and total settlement of a structure. Foundation Design Direct Shear Used to determine the consolidated drained shear strength of soil or rock. Bearing Capacity, Foundation Design, and Slope Stability Dry Density Used to determine the in-place density of natural, inorganic, fine-grained soils. Index Property Soil Behavior Expansion Used to measure the expansive potential of fine-grained soil and to provide a basis for swell potential classification. Foundation and Slab Design Gradation Used for the quantitative determination of the distribution of particle sizes in soil. Soil Classification Liquid & Plastic Limit, Plasticity Index Used as an integral part of engineering classification systems to characterize the fine-grained fraction of soils, and to specify the fine-grained fraction of construction materials. Soil Classification Permeability Used to determine the capacity of soil or rock to conduct a liquid or gas. Groundwater Flow Analysis pH Used to determine the degree of acidity or alkalinity of a soil. Corrosion Potential Resistivity Used to indicate the relative ability of a soil medium to carry electrical currents. Corrosion Potential R-Value Used to evaluate the potential strength of subgrade soil, subbase, and base course material, including recycled materials for use in road and airfield pavements. Pavement Thickness Design Soluble Sulfate Used to determine the quantitative amount of soluble sulfates within a soil mass. Exhibit C-5 REPORT TERMINOLOGY (Based on ASTM D653) Allowable Soil Bearing Capacity The recommended maximum contact stress developed at the interface of the foundation element and the supporting material. Alluvium Soil, the constituents of which have been transported in suspension by flowing water and subsequently deposited by sedimentation. Aggregate Base Course A layer of specified material placed on a subgrade or subbase usually beneath slabs or pavements. Backfill A specified material placed and compacted in a confined area. Bedrock A natural aggregate of mineral grains connected by strong and permanent cohesive forces. Usually requires drilling, wedging, blasting or other methods of extraordinary force for excavation. Bench A horizontal surface in a sloped deposit. Caisson (Drilled Pier or Shaft) A concrete foundation element cast in a circular excavation which may have an enlarged base. Sometimes referred to as a cast-in-place pier or drilled shaft. Coefficient of Friction A constant proportionality factor relating normal stress and the corresponding shear stress at which sliding starts between the two surfaces. Colluvium Soil, the constituents of which have been deposited chiefly by gravity such as at the foot of a slope or cliff. Compaction The densification of a soil by means of mechanical manipulation Concrete Slab-on- Grade A concrete surface layer cast directly upon a base, subbase or subgrade, and typically used as a floor system. Differential Movement Unequal settlement or heave between, or within foundation elements of structure. Earth Pressure The pressure exerted by soil on any boundary such as a foundation wall. ESAL Equivalent Single Axle Load, a criteria used to convert traffic to a uniform standard, (18,000 pound axle loads). Engineered Fill Specified material placed and compacted to specified density and/or moisture conditions under observations of a representative of a geotechnical engineer. Equivalent Fluid A hypothetical fluid having a unit weight such that it will produce a pressure against a lateral support presumed to be equivalent to that produced by the actual soil. This simplified approach is valid only when deformation conditions are such that the pressure increases linearly with depth and the wall friction is neglected. Existing Fill (or Man-Made Fill) Materials deposited throughout the action of man prior to exploration of the site. Existing Grade The ground surface at the time of field exploration. Exhibit C-6 REPORT TERMINOLOGY (Based on ASTM D653) Expansive Potential The potential of a soil to expand (increase in volume) due to absorption of moisture. Finished Grade The final grade created as a part of the project. Footing A portion of the foundation of a structure that transmits loads directly to the soil. Foundation The lower part of a structure that transmits the loads to the soil or bedrock. Frost Depth The depth at which the ground becomes frozen during the winter season. Grade Beam A foundation element or wall, typically constructed of reinforced concrete, used to span between other foundation elements such as drilled piers. Groundwater Subsurface water found in the zone of saturation of soils or within fractures in bedrock. Heave Upward movement. Lithologic The characteristics which describe the composition and texture of soil and rock by observation. Native Grade The naturally occurring ground surface. Native Soil Naturally occurring on-site soil, sometimes referred to as natural soil. Optimum Moisture Content The water content at which a soil can be compacted to a maximum dry unit weight by a given compactive effort. Perched Water Groundwater, usually of limited area maintained above a normal water elevation by the presence of an intervening relatively impervious continuous stratum. Scarify To mechanically loosen soil or break down existing soil structure. Settlement Downward movement. Skin Friction (Side Shear) The frictional resistance developed between soil and an element of the structure such as a drilled pier. Soil (Earth) Sediments or other unconsolidated accumulations of solid particles produced by the physical and chemical disintegration of rocks, and which may or may not contain organic matter. Strain The change in length per unit of length in a given direction. Stress The force per unit area acting within a soil mass. Strip To remove from present location. Subbase A layer of specified material in a pavement system between the subgrade and base course. Subgrade The soil prepared and compacted to support a structure, slab or pavement system. Appendix E Filterra Operations and Maintenance Manual Operation & Maintenance (OM) Manual v01 ® Bioretention Systems ENGINEERED SOLUTIONS www.ContechES.com/filterra | 800-338-1122 Table of Contents Overview • Filterra® General Description • Filterra® Schematic • Basic Operations • Design Maintenance • Maintenance Overview » Why Maintain? » When to Maintain? • Exclusion of Services • Maintenance Visit Summary • Maintenance Tools, Safety Equipment and Supplies • Maintenance Visit Procedure • Maintenance Checklist ® Bioretention Systems ENGINEERED SOLUTIONS www.ContechES.com/filterra | 800-338-1122 General Description The following general specifications describe the general operations and maintenance requirements for the Contech Engineered Solutions LLC stormwater bioretention filtration system, the Filterra®. The system utilizes physical, chemical and biological mechanisms of a soil, plant and microbe complex to remove pollutants typically found in urban stormwater runoff. The treatment system is a fully equipped, pre-constructed drop-in place unit designed for applications in the urban landscape to treat contaminated runoff. Stormwater flows through a specially designed filter media mixture contained in a landscaped concrete container. The mixture immobilizes pollutants which are then decomposed, volatilized and incorporated into the biomass of the Filterra® system’s micro/macro fauna and flora. Stormwater runoff flows through the media and into an underdrain system at the bottom of the container, where the treated water is discharged. Higher flows bypass the Filterra® to a downstream inlet or outfall. Maintenance is a simple, inexpensive and safe operation that does not require confined space access, pumping or vacuum equipment or specialized tools. Properly trained landscape personnel can effectively maintain Filterra® Stormwater systems by following instructions in this manual. www.ContechES.com/filterra | 800-338-1122 Basic Operations Filterra® is a bioretention system in a concrete box. Contaminated stormwater runoff enters the filter box through the curb inlet spreading over the 3-inch layer of mulch on the surface of the filter media. As the water passes through the mulch layer, most of the larger sediment particles and heavy metals are removed through sedimentation and chemical reactions with the organic material in the mulch. Water passes through the soil media where the finer particles are removed and other chemical reactions take place to immobilize and capture pollutants in the soil media. The cleansed water passes into an underdrain and flows to a pipe system or other appropriate discharge point. Once the pollutants are in the soil, the bacteria begin to break down and metabolize the materials and the plants begin to uptake and metabolize the pollutants. Some pollutants such as heavy metals, which are chemically bound to organic particles in the mulch, are released over time as the organic matter decomposes to release the metals to the feeder roots of the plants and the cells of the bacteria in the soil where they remain and are recycled. Other pollutants such as phosphorus are chemically bound to the soil particles and released slowly back to the plants and bacteria and used in their metabolic processes. Nitrogen goes through a very complex variety of biochemical processes where it can ultimately end up in the plant/bacteria biomass, turned to nitrogen gas or dissolves back into the water column as nitrates depending on soil temperature, pH and the availability of oxygen. The pollutants ultimately are retained in the mulch, soil and biomass with some passing out of the system into the air or back into the water. Design and Installation Each project presents different scopes for the use of Filterra® systems. To ensure the safe and specified function of the stormwater BMP, Contech reviews each application before supply. Information and help may be provided to the design engineer during the planning process. Correct Filterra® box sizing (by rainfall region) is essential to predict pollutant removal rates for a given area. The engineer shall submit calculations for approval by the local jurisdiction. The contractor is responsible for the correct installation of Filterra units as shown in approved plans. A comprehensive installation manual is available at www.conteches.com. Maintenance Why Maintain? All stormwater treatment systems require maintenance for effective operation. This necessity is often incorporated in your property’s permitting process as a legally binding BMP maintenance agreement. • Avoid legal challenges from your jurisdiction’s maintenance enforcement program. • Prolong the expected lifespan of your Filterra media. • Avoid more costly media replacement. • Help reduce pollutant loads leaving your property. Simple maintenance of the Filterra® is required to continue effective pollutant removal from stormwater runoff before discharge into downstream waters. This procedure will also extend the longevity of the living biofilter system. The unit will recycle and accumulate pollutants within the biomass, but is also subjected to other materials entering the throat. This www.ContechES.com/filterra | 800-338-1122 Exclusion of Services It is the responsibility of the owner to provide adequate irrigation when necessary to the plant of the Filterra® system. Clean up due to major contamination such as oils, chemicals, toxic spills, etc. will result in additional costs and are not covered under the Supplier maintenance contract. Should a major contamination event occur the Owner must block off the outlet pipe of the Filterra® (where the cleaned runoff drains to, such as drop inlet) and block off the throat of the Filterra®. The Supplier should be informed immediately. Maintenance Visit Summary Each maintenance visit consists of the following simple tasks (detailed instructions below). 1. Inspection of Filterra® and surrounding area 2. Removal of tree grate and erosion control stones 3. Removal of debris, trash and mulch 4. Mulch replacement 5. Plant health evaluation and pruning or replacement as necessary 6. Clean area around Filterra® 7. Complete paperwork Maintenance Tools, Safety Equipment and Supplies Ideal tools include: camera, bucket, shovel, broom, pruners, hoe/rake, and tape measure. Appropriate Personal Protective Equipment (PPE) should be used in accordance with local or company procedures. This may include impervious gloves where the type of trash is unknown, high visibility clothing and barricades when working in close proximity to traffic and also safety hats and shoes. A T-Bar or crowbar should be used for moving the tree grates (up to 170 lbs ea.). Most visits require minor trash removal and a full replacement of mulch. See below for actual number of bagged mulch that is required in each unit size. Mulch should be a double shredded, hardwood variety; do not use colored or dyed mulch. Some visits may require additional Filterra® engineered soil media available from the Supplier. Box Length Box Width Filter Surface Area (ft²) Volume at 3” (ft³) # of 2 ft³ Mulch Bags 4 4 16 4 2 6 4 24 6 3 8 4 32 8 4 6 6 36 9 5 8 6 48 12 6 10 6 60 15 8 12 6 72 18 9 13 7 91 23 12 www.ContechES.com/filterra | 800-338-1122 Maintenance Visit Procedure Keep sufficient documentation of maintenance actions to predict location specific maintenance frequencies and needs. An example Maintenance Report is included in this manual. 1. Inspection of Filterra® and surrounding area • Record individual unit before maintenance with photograph (numbered). Record on Maintenance Report (see example in this document) the following: 2. Removal of tree grate and erosion control stones • Remove cast iron grates for access into Filterra® box. • Dig out silt (if any) and mulch and remove trash & foreign items. 3. Removal of debris, trash and mulch • After removal of mulch and debris, measure distance from the top of the Filterra® engineered media soil to the bottom of the top slab. If this distance is greater than 12”, add Filterra® media (not top soil or other) to recharge to a 9” distance Record on Maintenance Report the following: Standing Water yes | no Damage to Box Structure yes | no Damage to Grate yes | no Is Bypass Clear yes | no If yes answered to any of these observations, record with close-up photograph (numbered). Record on Maintenance Report the following: Silt/Clay yes | no Cups/ Bags yes | no Leaves yes | no # of Buckets Removed ________ Record on Maintenance Report the following: Distance of Bottom of Top Slab (inches) ________ # of Buckets of Media Added ________ www.ContechES.com/filterra | 800-338-1122 4. Mulch replacement • Please see mulch specifications. • Add double shredded mulch evenly across the entire unit to a depth of 3”. • Ensure correct repositioning of erosion control stones by the Filterra® inlet to allow for entry of trash during a storm event. • Replace Filterra® grates correctly using appropriate lifting or moving tools, taking care not to damage the plant. 5. Plant health evaluation and pruning or replacement as necessary • Examine the plant’s health and replace if dead. • Prune as necessary to encourage growth in the correct directions 6. Clean area around Filterra® • Clean area around unit and remove all refuse to be disposed of appropriately. 7. Complete paperwork • Deliver Maintenance Report and photographs to appropriate location (normally Contech during maintenance contract period). • Some jurisdictions may require submission of maintenance reports in accordance with approvals. It is the responsibility of the Owner to comply with local regulations. Record on Maintenance Report the following: Height above Grate ________________(ft) Width at Widest Point ________________(ft) Health alive | dead Damage to Plant yes | no Plant Replaced yes | no www.ContechES.com/filterra | 800-338-1122 Maintenance Checklist Drainage System Failure Problem Conditions to Check Condition that Should Exist Actions Inlet Excessive sediment or trash accumulation. Accumulated sediments or trash impair free flow of water into Filterra. Inlet should be free of obstructions allowing free distributed flow of water into Filterra. Sediments and/or trash should be removed. Mulch Cover Trash and floatable debris accumulation. Excessive trash and/or debris accumulation. Minimal trash or other debris on mulch cover. Trash and debris should be removed and mulch cover raked level. Ensure bark nugget mulch is not used. Mulch Cover “Ponding” of water on mulch cover. “Ponding” in unit could be indicative of clogging due to excessive fine sediment accumulation or spill of petroleum oils. Stormwater should drain freely and evenly through mulch cover. Recommend contact manufacturer and replace mulch as a minimum. Vegetation Plants not growing or in poor condition. Soil/mulch too wet, evidence of spill. Incorrect plant selection. Pest infestation. Vandalism to plants. Plants should be healthy and pest free. Contact manufacturer for advice. Vegetation Plant growth excessive. Plants should be appropriate to the species and location of Filterra. Trim/prune plants in accordance with typical landscaping and safety needs. Structure Structure has visible cracks. Cracks wider than 1/2 inch or evidence of soil particles entering the structure through the cracks. Vault should be repaired. Maintenance is ideally to be performed twice annually. ENGINEERED SOLUTIONS © 2015 Contech Engineered Solutions LLC Revised 6/22/2015 may include trash, silt and leaves etc. which will be contained within the void below the top grate and above the mulch layer. Too much silt may inhibit the Filterra’s® flow rate, which is the reason for site stabilization before activation. Regular replacement of the mulch stops accumulation of such sediment. When to Maintain? Contech includes a 1-year maintenance plan with each system purchase. Annual included maintenance consists of a maximum of two (2) scheduled visits. Additional maintenance may be necessary depending on sediment and trash loading (by Owner or at additional cost). The start of the maintenance plan begins when the system is activated for full operation. Full operation is defined as the unit installed, curb and gutter and transitions in place and activation (by Supplier) when mulch and plant are added and temporary throat protection removed. Activation cannot be carried out until the site is fully stabilized (full landscaping, grass cover, final paving and street sweeping completed). Maintenance visits are scheduled seasonally; the spring visit aims to clean up after winter loads including salts and sands while the fall visit helps the system by removing excessive leaf litter. It has been found that in regions which receive between 30-50 inches of annual rainfall, (2) two visits are generally required; regions with less rainfall often only require (1) one visit per annum. Varying land uses can affect maintenance frequency; e.g. some fast food restaurants require more frequent trash removal. Contributing drainage areas which are subject to new development wherein the recommended erosion and sediment control measures have not been implemented may require additional maintenance visits. Some sites may be subjected to extreme sediment or trash loads, requiring more frequent maintenance visits. This is the reason for detailed notes of maintenance actions per unit, helping the Supplier and Owner predict future maintenance frequencies, reflecting individual site conditions. Owners must promptly notify the (maintenance) Supplier of any damage to the plant(s), which constitute(s) an integral part of the bioretention technology. Owners should also advise other landscape or maintenance contractors to leave all maintenance to the Supplier (i.e. no pruning or fertilizing). Corrosion Potential Unconfined Compression To obtain the approximate compressive strength of soils that possess sufficient cohesion to permit testing in the unconfined state. Bearing Capacity Analysis for Foundations Water Content Used to determine the quantitative amount of water in a soil mass. Index Property Soil Behavior C Gravels with 5 to 12% fines require dual symbols: GW-GM well-graded gravel with silt, GW-GC well-graded gravel with clay, GP-GM poorly graded gravel with silt, GP-GC poorly graded gravel with clay. D Sands with 5 to 12% fines require dual symbols: SW-SM well-graded sand with silt, SW-SC well-graded sand with clay, SP-SM poorly graded sand with silt, SP-SC poorly graded sand with clay E Cu = D60/D10 Cc = 10 60 2 30 D x D (D ) F If soil contains 15% sand, add “with sand” to group name. G If fines classify as CL-ML, use dual symbol GC-GM, or SC-SM. H If fines are organic, add “with organic fines” to group name. I If soil contains 15% gravel, add “with gravel” to group name. J If Atterberg limits plot in shaded area, soil is a CL-ML, silty clay. K If soil contains 15 to 29% plus No. 200, add “with sand” or “with gravel,” whichever is predominant. L If soil contains 30% plus No. 200 predominantly sand, add “sandy” to group name. M If soil contains 30% plus No. 200, predominantly gravel, add “gravelly” to group name. N PI 4 and plots on or above “A” line. O PI 4 or plots below “A” line. P PI plots on or above “A” line. Q PI plots below “A” line. Silt or Clay Descriptive Term(s) of other constituents N (HP) (T) (DCP) (PID) (OVA) < 15 15 - 29 > 30 Term PLASTICITY DESCRIPTION Water levels indicated on the soil boring logs are the levels measured in the borehole at the times indicated. Groundwater level variations will occur over time. In low permeability soils, accurate determination of groundwater levels is not possible with short term water level observations. Water Level After a Specified Period of Time Water Level After a Specified Period of Time Water Initially Encountered Standard Penetration Test Unless otherwise noted, Latitude and Longitude are approximately determined using a hand-held GPS device. The accuracy of such devices is variable. Surface elevation data annotated with +/- indicates that no actual topographical survey was conducted to confirm the surface elevation. Instead, the surface elevation was approximately determined from topographic maps of the area. Standard Penetration Test Resistance (Blows/Ft.) Hand Penetrometer Torvane Dynamic Cone Penetrometer Photo-Ionization Detector Organic Vapor Analyzer STRENGTH TERMS Standard Penetration or N-Value Blows/Ft. Descriptive Term (Consistency) Descriptive Term (Density) CONSISTENCY OF FINE-GRAINED SOILS (50% or more passing the No. 200 sieve.) Consistency determined by laboratory shear strength testing, field visual-manual procedures or standard penetration resistance Standard Penetration or N-Value Blows/Ft. (More than 50% retained on No. 200 sieve.) Density determined by Standard Penetration Resistance RELATIVE DENSITY OF COARSE-GRAINED SOILS Hard > 30 > 50 Very Stiff 15 - 30 Stiff Medium Stiff Very Soft 0 - 1 Medium Dense Loose Soft Very Dense Dense 30 - 50 8 - 15 10 - 29 4 - 8 4 - 9 2 - 4 Very Loose 0 - 3 SILT OR CLAY 4 D30 D10 %Gravel %Sand 4 - 5.5 14 - 15.5 3/8 3 100 3 2 140 COBBLES GRAVEL SAND USCS Classification 41.5 56.6 D60 coarse medium Boring ID Depth Boring ID Depth GRAIN SIZE DISTRIBUTION ASTM D422 4 - 5.5 14 - 15.5 CLAYEY SAND (SC) POORLY GRADED SAND with SILT and GRAVEL (SP-SM) PROJECT NUMBER: 20165027 PROJECT: The Green Solution SITE: 810 North College Avenue Fort Collins, Colorado CLIENT: Manhard Consulting, Ltd. Centennial, Colorado EXHIBIT: B-3 1901 Sharp Point Dr Ste C Fort Collins, CO LABORATORY TESTS ARE NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GRAIN SIZE: USCS-2 20165027.GPJ 35159097 - ATTERBERG ISSUE.GPJ 4/1/16 abbreviations. PROJECT: The Green Solution PERCENT FINES WATER CONTENT (%) ATTERBERG LIMITS LL-PL-PI Surface Elev.: 4968.68 (Ft.) ELEVATION (Ft.) SAMPLE TYPE WATER LEVEL OBSERVATIONS DEPTH (Ft.) 5 10 15 20 FIELD TEST RESULTS DEPTH LOCATION See Exhibit A-2 Latitude: 40.598046° Longitude: -105.076414° At completion of drilling After 24 hours WATER LEVEL OBSERVATIONS Exhibit: A-4 the design and specifications. Terracon also should be retained to provide observation and testing services during grading, excavation, dry well construction and other earth-related construction phases of the project. The analysis and recommendations presented in this report are based upon the data obtained from the boring performed at the indicated location and from other information discussed in this report. This report does not reflect variations that may occur between boring, across the site, or due to the modifying effects of construction or weather. The nature and extent of such variations may not become evident until during or after construction. If variations appear, we should be immediately notified so that further evaluation and supplemental recommendations can be provided. The scope of services for this project does not include either specifically or by implication any environmental or biological (e.g., mold, fungi, and bacteria) assessment of the site or identification PROPOSED DRAINAGE BASIN DRAINAGE BASIN OUTLINE DESIGN POINT PROPOSED FLOW PATH PROPOSED SWALE PATH EXISTING FLOW PATH PROPOSED EMERGENCY OVERFLOW PATH EXISTING STORM PROPOSED STORM LEGEND 1 BASIN AREA AC. C2 C100 0 SCALE: 1"=10' 5 10 20 PROJ. MGR.: DRAWN BY: DATE: OF SHEET PROJ. ASSOC.: DATE REVISIONS DRAWN BY c 2016 MANHARD CONSULTING, LTD. ALL RIGHTS RESERVED TM PROPOSED DRAINAGE PLAN THE GREEN SOLUTION 810 N COLLEGE AVENUE FORT COLLINS, CO TGSFCCO01 ---- 1/25/16 JAR JAR DJM Plotted: 4/25/2016 3:26 PM Dwg Name: P:\Tgsfcco01\Documents\StormWater Reports\Preliminary Stormwater Reports\PR DNG.dwg Updated By: JRentz FOR LOCATING UNKNOWN UNDERGROUND UTILITIES. 3. THESE PLANS HAVE BEEN REVIEWED BY THE CITY FOR CONCEPT ONLY. THE REVIEW DOES NOT IMPLY RESPONSIBILITY BY THE REVIEWING DEPARTMENT, THE CITY ENGINEER, OR THE CITY FOR ACCURACY OR CORRECTNESS OF THE CALCULATIONS. FURTHERMORE, THE REVIEW DOES NOT IMPLY THAT THE QUANTITIES OF THE ITEMS ON THE PLANS ARE THE FINAL QUANTITIES REQUIRED. THE REVIEW SHALL NOT BE CONSTRUED IN ANY REASON AS ACCEPTANCE OF FINANCIAL RESPONSIBILITY BY THE CITY FOR ADDITIONAL QUANTITIES OF ITEMS SHOWN THAT MAY BE REQUIRED DURING THE CONSTRUCTION PHASE. 4. PRIOR TO THE COMMENCEMENT OF ANY CONSTRUCTION, THE CONTRACTOR MUST GIVE THE CITY ENGINEERING DEPARTMENT (970-221-6605) AND THE EROSION CONTROL INSPECTOR (970-221-6700) TWENTY-FOUR (24) HOURS ADVANCE NOTICE. INITIAL EROSION CONTROL MEASURES MUST BE INSTALLED AND A SITE INSPECTION BY THE EROSION CONTROL INSPECTOR IS REQUIRED BEFORE COMMENCING CONSTRUCTION ACTIVITIES. 5. MAINTENANCE OF ONSITE DRAINAGE FACILITIES SHALL BE THE RESPONSIBILITY OF THE PROPERTY OWNERS. 6. ALL RECOMMENDATIONS OF THE FINAL DRAINAGE AND EROSION CONTROL STUDY FOR THIS DEVELOPMENT BY (ENGINEERING FIRM) MUST BE MET. 7. PRIOR TO FINAL INSPECTION AND ACCEPTANCE BY THE CITY, CERTIFICATION OF THE DRAINAGE FACILITIES BY A COLORADO REGISTERED PROFESSIONAL ENGINEER MUST BE SUBMITTED TO AND APPROVED BY THE CITY STORMWATER DEPARTMENT. (INCLUDING THE APPLICABLE NOTE AS SET FORTH BELOW) FOR COMMERCIAL AND MULTI-FAMILY DEVELOPMENTS, CERTIFICATION OF ALL DRAINAGE FACILITIES SHALL BE SUBMITTED TO THE CITY STORMWATER DEPARTMENT AT LEAST TWO WEEKS PRIOR TO THE RELEASE OF A CERTIFICATE OF OCCUPANCY. INDIVIDUAL LOT CERTIFICATION, ELEVATION CERTIFICATION, OR FLOODPROOFING CERTIFICATION, AS SPECIFIED IN THE DEVELOPMENT AGREEMENT, MUST BE SUBMITTED TO THE CITY STORMWATER DEPARTMENT AT LEAST TWO WEEKS PRIOR TO THE RELEASE OF A CERTIFICATE OF OCCUPANCY FOR SUCH LOT. FOR SINGLE FAMILY DEVELOPMENTS, CERTIFICATION OF ALL DRAINAGE FACILITIES MUST BE SUBMITTED TO THE CITY STORMWATER DEPARTMENT IN ACCORDANCE WITH ALL CONDITIONS AS PRESCRIBED BY THE DEVELOPMENT AGREEMENT ASSOCIATED WITH THIS DEVELOPMENT. INDIVIDUAL LOT CERTIFICATION, ELEVATION CERTIFICATION, OR FLOODPROOFING CERTIFICATION, AS SPECIFIED IN THE DEVELOPMENT AGREEMENT, MUST BE SUBMITTED TO THE CITY STORMWATER DEPARTMENT AT LEAST ONE WEEK PRIOR TO THE RELEASE OF A CERTIFICATE OF OCCUPANCY FOR SUCH LOT. 8. IF DEWATERING IS USED TO INSTALL UTILITIES, AND DISCHARGE WILL BE INTO THE STREET, GUTTER, STORM SEWER, CHANNEL, IRRIGATION DITCH, OR ANY WATERS OF THE STATE A STATE CONSTRUCTION DEWATERING INDUSTRIAL WASTEWATER DISCHARGE PERMIT IS REQUIRED. 9. ALL LAND DISTURBING ACTIVITIES GREATER THAN OR EQUAL TO ONE ACRE MUST COMPLY WITH THE STATE OF COLORADO PERMITTING PROCESS FOR STORMWATER DISCHARGES ASSOCIATED WITH CONSTRUCTION ACTIVITY. FOR MORE INFORMATION CONTACT THE COLORADO DEPARTMENT OF PUBLIC HEALTH AND ENVIRONMENT, WATER QUALITY CONTROL DIVISION, AT 303-692-3500 OR REFER TO THE WEB SITE AT HTTP://WWW.CDPHE.STATE.CO.US/WQ/PERMITSUNIT/ . 10. BENCHMARK: CITY OF FORT COLLINS VERTICAL CONTROL LOCATED AT THE ELEVATION = 4968.74 FEET, NAVD88. 11. IF FILL OR DREDGED MATERIAL IS DISCHARGED INTO WATERS OF THE UNITED STATES, A USACE 404 PERMIT IS REQUIRED. 12. IF CONSTRUCTION AFFECTS ANY COLORADO HIGHWAY, A COLORADO DEPARTMENT OF TRANSPORTATION RIGHT-OF-WAY PERMIT IS REQUIRED. Survey Area Data: Version 10, Sep 22, 2015 Soil map units are labeled (as space allows) for map scales 1:50,000 or larger. Date(s) aerial images were photographed: Apr 22, 2011—Apr 28, 2011 The orthophoto or other base map on which the soil lines were compiled and digitized probably differs from the background imagery displayed on these maps. As a result, some minor shifting of map unit boundaries may be evident. Hydrologic Soil Group—Larimer County Area, Colorado Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 12/4/2015 Page 2 of 4