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HomeMy WebLinkAboutST. ELIZABETH ANN SETON CHURCH EXPANSION - FDP - FDP180003 - SUBMITTAL DOCUMENTS - ROUND 1 - EROSION CONTROL LETTER/REPORTCOLORADO CIVIL GROUP, INC. EROSION & DUST CONTROL REPORT FOR ST. ELIZABETH ANN SETON CATHOLIC CHURCH EXPANSION CITY OF FORT COLLINS FEBRUARY 14, 2018 Colorado Civil Group, Inc. February 14, 2018 Mr. Jesse Schlam, CFM City of Fort Collins 281 N College Avenue Fort Collins, CO 80524 Re: St. Elizabeth Ann Seton Catholic Church Expansion Project No. 0031.0012.01 Dear Mr. Schlam, We are pleased to re-submit this Erosion and Dust Control Report for the St. Elizabeth Ann Seton Catholic Church Expansion project. This report was prepared based on current City of Fort Collins and UDFCD storm drainage criteria. Please let me know if you have any questions or comments. Sincerely, COLORADO CIVIL GROUP, INC. David A. Huwa, PE St. Elizabeth Ann Seton Catholic Church Expansion Erosion & Dust Control Report Colorado Civil Group, Inc. i Table of Contents 1 Introduction .............................................................................................................................................................. 1 1.1 Report Objectives (I.B.1 – I.B.4) ........................................................................................................................ 1 1.2 ECP Administrator (I.C.3.a) ............................................................................................................................... 1 2 Site Description (I.C.1) .............................................................................................................................................. 2 2.1 Site Location ..................................................................................................................................................... 2 2.2 Existing Site Description ................................................................................................................................... 3 2.3 Proposed Site Description ................................................................................................................................ 4 3 Identification of Pollutant Sources ........................................................................................................................... 5 3.1 Disturbed or Stored Soils (I.C.3.b.1) ................................................................................................................. 5 3.2 Vehicle Tracking of Sediments (I.C.3.b.2) ......................................................................................................... 6 3.3 Management of Contaminated Soils (I.C.3.b.3) ............................................................................................... 6 3.4 Loading and Unloading Operations (I.C.3.b.4) ................................................................................................. 6 3.5 Outdoor Storage Activities (I.C.3.b.5) ............................................................................................................... 6 3.6 Vehicle and Equipment Maintenance and Fueling (I.C.3.b.6) .......................................................................... 6 3.7 Significant Dust or Particulate Generating Processes (I.C.3.b.7) ...................................................................... 7 3.8 Routine Maintenance Activities (I.C.3.b.8) ....................................................................................................... 7 3.9 On-Site Waste Management Practices (I.C.3.b.9) ............................................................................................ 7 3.10 Concrete Truck Washout (I.C.3.b.10) ............................................................................................................... 7 3.11 Non-Industrial Waste Sources (I.C.3.b.12) ....................................................................................................... 7 3.12 Other Areas or Procedures where Potential Spills Can Occur (I.C.3.b.13) ....................................................... 8 4 Stormwater Management Controls (I.C.3.c) ............................................................................................................ 8 4.1 Four-Step Process ............................................................................................................................................. 8 4.2 Temporary BMPs ............................................................................................................................................ 10 4.3 Permanent BMPs ............................................................................................................................................ 12 5 BMPs for Material Handling and Spill Prevention (I.C.3.c.4) .................................................................................. 12 6 Final Stabilization and Ultimate Stormwater Management (I.C.4) ........................................................................ 13 7 Construction Site Inspection and Maintenance (I.C.5, I.D.6, I.D.7) ........................................................................ 13 St. Elizabeth Ann Seton Catholic Church Expansion Erosion & Dust Control Report Colorado Civil Group, Inc. ii Figures and Tables Figure 1-1: Vicinity Map ................................................................................................................................................ 2 Table 2-1: Anticipated Construction Phases ................................................................................................................. 4 Appendices Appendix A: Soils Information ...................................................................................................................................... A Appendix B: Grading and Erosion Control Plan and Construction Details ................................................................... B St. Elizabeth Ann Seton Catholic Church Expansion Erosion & Dust Control Report Colorado Civil Group, Inc. 1 1 Introduction 1.1 Report Objectives (I.B.1 – I.B.4) The objective of this report is to create an Erosion Control Plan (ECP) to “identify possible pollutant sources to stormwater and to set out Best Management Practices (BMPs) that, when implemented, will reduce or eliminate any possible water quality impacts.” (from Colorado’s Stormwater Program Fact Sheet) More specifically, this report covers each facility in the General Permit Application for Stormwater Discharges Associated with Construction Activity (Stormwater Construction Permit). This report identifies potential pollutant sources which could adversely affect the quality of the discharged stormwater and suggests measures that can be implemented to reduce stormwater pollutants associated with construction activity. All measures described within this report are in accordance with good engineering practices, which include installation, implementation, and maintenance requirements, and must be updated in accordance with Part I.D.5.c of the Stormwater Construction Permit, to ensure compliance with the terms and conditions of the permit. Furthermore, any potential pollutant that can reasonably be expected during construction activity through final stabilization must be identified and any possible water quality impacts must be reduced or eliminated by implementing the suggested measures found within this report. 1.2 ECP Administrator (I.C.3.a) The ECP Administrator is responsible for developing, implementing, maintaining, and revising the ECP. The ECP Administrator will be assigned by the General Contractor and should be noted below when the construction contract is awarded: Name: _____________________________ Title: _____________________________ Company: _____________________________ Address: _____________________________ _____________________________ Phone: _____________________________ Email: _____________________________ St. Elizabeth Ann Seton Catholic Church Expansion Erosion & Dust Control Report Colorado Civil Group, Inc. 2 2 Site Description (I.C.1) 2.1 Site Location The St. Elizabeth Ann Seton (SEAS) site, which is approximately 11.7 acres in area, is located in the Southwest Quarter of Section 6, Township 7 North, Range 68 West of the 6th Principal Meridian, City of Fort Collins, County of Larimer, Colorado. The site is bounded on the north by Seton Street and on the west by South Lemay Avenue, on the South by Southridge Greens Blvd., and on the east by Southridge Golf Course. A vicinity map is presented in Figure 1-1 below. The project area is generally located at Latitude 40° 30’35.82” and Longitude -105° 03’23.96”. The site is part of the Fossil Creek Drainage Basin and is included as part of the Fossil Creek Drainage Base Master Drainageway Planning Restudy Phase A. Figure 1-1: Vicinity Map ST. ELIZABETH ANN SETON S LEMAY AVE S COLLGE AVE SOUTHRIDGE GREENS BLVD. FOSSILL CREEK PKWY St. Elizabeth Ann Seton Catholic Church Expansion Erosion & Dust Control Report Colorado Civil Group, Inc. 3 2.2 Existing Site Description 2.2.1 Existing Physical Characteristics (I.C.1.c) The SEAS site consists of the existing St. Elizabeth Ann Seton Church, existing parking lots, outdoor sheds, and an existing stormwater drainage system. The existing drainage system includes a detention pond at the southwest corner of the property. The existing detention pond has been designed with a Water Quality Capture Volume (WQCV), orifice plate, and outlet structure. Vegetative cover observed at the site are estimated at 95% in pervious areas, which generally consists of native grasses, sod and landscaping. There are no changes planned for the existing drainage infrastructure. 2.2.2 Existing Soil Properties (I.C.1.d) Soil properties described in this section were determined from the Natural Resources Conservation Service (NRCS) website using the Web Soil Survey to compile and present the data. The soil on the SEAS site are in Hydrologic Soil Group B and C, which is defined as soils having a moderate to slow infiltration when thoroughly wet. Roughly 75% of the soils are Group B, and for this reason, infiltration based BMPs were considered a good option for the project site. The soils on site fall into the wind erodibility groups from 3 to 6 and have a wind erosion index between 48 to 86. Wind erodibility groups range from 1 to 8 where group 1 is the most susceptible to wind erosion and group 8 is the least susceptible. The wind erodibility index is a numerical value, ranging from 0 to 310, indicating the susceptibility of soil to wind erosion, or the tons per acre per year that can be expected to be lost to wind erosion. The erosion potential due to wind in disturbed areas is considered moderate for the project site. Several exhibits are provided in Appendix A that show the soil properties presented in this section. 2.2.3 Closest Receiving Waters The project site is located within the Fossil Creek Drainage Basin. Runoff generated on-site is conveyed to the southwest corner of the property where an existing water quality and detention pond is situated. Runoff released at a controlled rate is conveyed south under Southridge Greens Blvd., and ultimately to Fossil Creek which is approximately 900 feet south of the project site. Any on-site spills will be routed to the water quality pond, where cleanup can occur. St. Elizabeth Ann Seton Catholic Church Expansion Erosion & Dust Control Report Colorado Civil Group, Inc. 4 If spills pass through the water quality pond, they will enter the storm sewer system in Lemay Ave. and empty into Fossil Creek. 2.3 Proposed Site Description 2.3.1 Proposed Construction Activity (I.C.1.a and I.C.1.b) The proposed improvements include a building expansion, grading improvements including a rain garden, general concrete paving, a concrete paved access for emergency fire equipment, and the reconstruction of three driveway entrances. Several storm drainage improvements will also be required due to the additional impervious area. Additionally, the Final Drainage Report includes an evaluation of a future impervious improvement, likely an onsite residence for the Church’s Father and additional parking, and will be located in undeveloped areas of the site. The future impervious area will be included in the LID and detention requirements discussed in the Final Drainage Report. The proposed construction activity will begin with the installation of erosion control devices. Silt fence, straw wattles, and any necessary inlet protection will be installed to prevent sediment transportation. After the erosion control devices are installed, construction will likely begin with earthwork activities for building construction. As building construction is nearing completion, the remaining site earthwork, grading, and paving activities are expected. The re- construction of the three driveway entrances are expected near the end of construction activities. Once site construction activities are generally complete, site landscaping and re-seeding will occur. Disturbed areas that are not paved will be landscaped. After these steps are complete the site will reach final stabilization. Table 2-1 shows the anticipated construction activities within each phase of site construction. Table 2-1: Anticipated Construction Phases Construction Activity Site Development Phase Erosion Control Installation Phase I Earthwork for Building Construction Phase II Remaining Site Earthwork, Grading Phase III Re-construction of Driveway Entrances, Fire Access Construction Phase IV Landscaping Phase V Final Stabilization Phase VI St. Elizabeth Ann Seton Catholic Church Expansion Erosion & Dust Control Report Colorado Civil Group, Inc. 5 2.3.2 Proposed Physical Characteristics (I.C.1.a) Some of the physical characteristics of the site will be modified with the improvements, which includes additional impervious surfacing and a rain garden. The proposed drainage patterns will generally follow the existing drainage patterns. There are no proposed changes in soil type, hydrologic soil group, or drainage class. The imperviousness of the site will increase with the improvements, which will increase runoff to the detention pond. 2.3.3 Proposed Controls Controls are necessary once construction begins and must continue until the project is complete, leaving no exposed soils. These controls are critical to ensuring that downstream receiving waters are protected from contamination due to soil erosion caused by wind and surface runoff, as well as any potential chemical or biological contamination anticipated due to construction activities. Controls used for site development are discussed in greater detail in Section 4. 3 Identification of Pollutant Sources This section of the Erosion and Dust Control report identifies pollutant sources generally expected with construction activities. Since it is not possible to know all of the construction activities that will occur on-site during the design phase of the project, it is critical that the Contractor be aware of all construction activities and their potential to contaminate stormwater and, if needed, install controls to prevent contamination. The following sections describe pollutant sources in detail, and Section 4 of this report details the controls necessary to prevent contamination. 3.1 Disturbed or Stored Soils (I.C.3.b.1) Approximately 1.5 acres of the site will disturbed with the construction activities. Once soils have been disturbed, they do not retain the same compaction as in their native state, therefore surface runoff can cause more soil erosion than was historically observed. Stockpiles shall be placed in an area where the proposed BMPs (i.e. wattles or silt fence) will prevent the migration of soils into the public streets and stormwater system. Disturbed soils ultimately need to be stabilized, which is achieved through re-vegetation or construction of impervious surface. St. Elizabeth Ann Seton Catholic Church Expansion Erosion & Dust Control Report Colorado Civil Group, Inc. 6 3.2 Vehicle Tracking of Sediments (I.C.3.b.2) Vehicle tracking of sediments will occur throughout the construction process. The implementation of street sweeping practices and keeping vehicles on paved surfaces is critical in reducing pollutants during construction. Vehicle tracking control pads will reduce the tracking of sediments. Due to the anticipated construction activities, vehicle tracking control pads may not be most efficient at property boundaries as they are paved surfaces. So vehicle tracking control pads will be more effective in areas where vehicle traffic leaves disturbed soils and enters paved surfaces like parking lots. 3.3 Management of Contaminated Soils (I.C.3.b.3) In the event that soils are found to be contaminated on-site, the ECP Administrator should be notified. Proper procedures should be followed based on the type and extent of soil contamination. 3.4 Loading and Unloading Operations (I.C.3.b.4) Loading and unloading operations should occur within the stabilized staging area identified on the plans, or otherwise worked out with owner. If located on paved surface, downstream storm drainage facilities will need BMPs, such as curb socks or gravel inlet protection. If on unpaved surfaces, silt fence or straw wattles can be used around the perimeter of the staging area to prevent contamination. 3.5 Outdoor Storage Activities (I.C.3.b.5) Construction materials may be stored on-site with the construction of the project. Many potential contaminants may be brought to the site as part of the site and building construction activities. Stored materials should occur in one location on-site, and preferably be located within the staging area. Stored liquids and materials should be covered with an impermeable tarp to prevent transportation during precipitation events. 3.6 Vehicle and Equipment Maintenance and Fueling (I.C.3.b.6) Due to the planned construction activities, is anticipated that equipment maintenance and fueling will occur on-site. These procedures must only be allowed to occur only in one designated area on-site to limit spillage of maintenance liquids/lubricants and fuel. An impermeable tarp that prevents fuel and other liquids from infiltrating the soil must cover the fueling area. Proper disposal of contaminated soil must occur after the construction is complete or at frequent intervals, if necessary. St. Elizabeth Ann Seton Catholic Church Expansion Erosion & Dust Control Report Colorado Civil Group, Inc. 7 3.7 Significant Dust or Particulate Generating Processes (I.C.3.b.7) Dust or particulate generation is typical in the northern front range of Colorado, and can happen anytime during the year. The use of water for dust control is the most common practice for minimizing particulate generation. Another possible preventative technique would be to minimize vehicular traffic on days with high winds. The City of Fort Collins has passed a Dust Control Ordinance and created a Fugitive Dust Manual as a guide for owners, developers, and contractors. The manual presents common activities that produce fugitive dust, and also recommends BMPs and controls to eliminate or reduce fugitive dust. 3.8 Routine Maintenance Activities (I.C.3.b.8) Other than typical vehicle repair and maintenance, there are no other anticipated maintenance activities that require additional controls. 3.9 On-Site Waste Management Practices (I.C.3.b.9) Nearly all construction sites must implement some sort of waste management practice and the this project is no exception. Portable toilets and construction debris must be located in areas where, if spillage occurs, it would not enter the public streets or stormwater system. Portable toilets must be anchored and regularly cleaned. Construction debris must be contained in dumpsters and also regularly emptied. 3.10 Concrete Truck Washout (I.C.3.b.10) Concrete construction is planned for this project, so a designated area for the concrete truck washout is needed. Part I.D.3.c of the Stormwater Construction Permit must be followed in order to allow the conditional discharge of concrete washout water to the ground. Other equipment washing may occur throughout the construction process as well, so this equipment should be washed in the same area as the concrete truck washout. The concrete washout area shall be constructed per the Urban Drainage Flood Control District (UDFCD) detail and will require a vehicle tracking control pad, which shall be constructed per the UDFCD detail. It may be impractical to establish a standard concrete truck washout, so as an alternative, eco-pans may be used and disposed of properly. 3.11 Non-Industrial Waste Sources (I.C.3.b.12) One location should be setup for disposing of liquid and solid wastes generated during the construction process. Containers should be kept closed at all times to prevent St. Elizabeth Ann Seton Catholic Church Expansion Erosion & Dust Control Report Colorado Civil Group, Inc. 8 waste from blowing off-site during days with high winds. Construction debris can be stored until removed from the site and disposed of properly. 3.12 Other Areas or Procedures where Potential Spills Can Occur (I.C.3.b.13) There are no other areas or procedures to our knowledge where potential spills can occur with the construction of the SEAS project. 4 Stormwater Management Controls (I.C.3.c) Stormwater management controls are commonly referred to as Best Management Practices, or BMPs. The typical duration of use for individual BMP's can vary depending on the type of BMP, the function of the BMP, the type of construction, and the duration of construction activities. All projects require both temporary and permanent BMPs to be installed during and following construction activities. The following sections will identify both temporary and permanent BMPs that are to be used with proposed project. The implementation phase is provided for each BMP in addition to the inspection interval. Anticipated BMPs to be used with the SEAS project have been identified on the Grading and Erosion Control Plan, the BMP’s are provided in Appendix B. During the design phase, it can be difficult to identify all necessary preventative measures needed to prevent receiving water contamination; therefore, the Contractor must monitor the ongoing construction and install any BMP, whether listed in the report or not, necessary to prevent contamination. The ECP Administrator should modify the Grading & Erosion Control Plan as necessary to document BMP installation and maintenance during the life of the project. 4.1 Four-Step Process The selection of BMPs is part of the “Four-Step Process for Stormwater Quality Management” as outlined by UDFCD and adopted by the City of Fort Collins. The following sections explain that four-step process. 4.1.1 Step 1: Runoff Reduction The first step in stormwater quality management is to reduce runoff peaks, volumes, and pollutant loads from urbanizing areas by implementing Low Impact Development (LID) strategies. LID practices include reducing unnecessary impervious areas and routing runoff from impervious surfaces over permeable areas to slow runoff and promote infiltration. The SEAS project does include an increase in impervious area with the construction of the proposed improvements detailed above. Runoff generated St. Elizabeth Ann Seton Catholic Church Expansion Erosion & Dust Control Report Colorado Civil Group, Inc. 9 from the new impervious areas is discharged onto a vegetated buffer prior to entering the existing detention pond, which will promote filtering of the runoff and some infiltration which helps to reduce the peak discharge. The buffer width varies from roughly 50 feet to more than 100 feet. 4.1.2 Step 2: Treat and Slowly Release Runoff After reducing the runoff from a site, the second step in stormwater quality management is to capture and slowly release a Water Quality Capture Volume (WQCV). WQCV facilities may include bioretention, extended detention basins, sand filters, constructed wetland ponds, and retention ponds. The existing detention pond was designed with a WQCV and outlet. No changes to these facilities are proposed with the SEAS project. To address the additional impervious areas, and City of Fort Collins drainage requirements, a Rain Garden has been designed and will be constructed to capture a portion of the sites runoff prior to entering the detention pond. Since the proposed improvements span a wide area, it is difficult to capture all of the discharged runoff efficiently, so an ‘area-swap’ is being proposed, as outlined in the Final Drainage Report. The proposed rain garden will allow for infiltration and reducing the peak discharge from impervious areas of the site. 4.1.3 Step 3: Stabilize Drainageways Although steps 1 and 2 help to minimize the effects of runoff on downstream drainageways, natural drainageways are often subject to bed and bank erosion due to increases in the frequency, rate, duration, and volume of runoff. Step 3 includes measures to prevent drainageway erosion. There are no proposed drainageways planned for the SEAS site. By implementing steps 1 and 2, the project site does its part to reduce drainageway erosion downstream. Additionally, all disturbed areas will either be paved, re-seeded or landscaped in order to achieve stabilization. All runoff from the site enters the existing detention pond, so off-site downstream drainageways should be adequately protected. 4.1.4 Step 4: Implementation of Source Controls The final step in stormwater quality management is source control. Site specific needs such as material storage or other site operations require consideration of St. Elizabeth Ann Seton Catholic Church Expansion Erosion & Dust Control Report Colorado Civil Group, Inc. 10 targeted source control BMPs. These BMPs are shown on the Grading Plan, found in Appendix B of this report. Expected source erosion control BMP’s include straw wattles, inlet and outlet protection, and re-seeding. 4.2 Temporary BMPs The following description of temporary BMPs is organized to provide some indication as to the order in which the BMPs are to be installed. This order is based on typical construction activity sequencing. Temporary BMP details can be found in Appendix B of this report. 4.2.1 Vehicle Tracking Control Pad (I.C.3.c.6) Vehicle tracking control pads should be one of the first BMPs installed during the construction process. Additional pads should be added if more than one exit location is being used for construction traffic and will be required with the concrete washout. Vehicle tracking control pads may also be required to access the materials stockpile or the batch plant, if applicable. Vehicle tracking control pads will be installed where shown on the Grading and Erosion Control Plan and any additional locations determined by the Contractor, and should be installed per the details provided in Appendix B. Implementation Phase (I.C.3.c.3) - Phase I Inspection Interval (I.D.6 and I.D.7) – Every 14 days and within 24 hours following precipitation or snow melt 4.2.2 Stabilized Staging Area(Structural - I.C.3.c.1) A stabilized staging area should be established to ensure there is a large enough area to fully contain parking, storage, and unloading and loading operations. A possible location for the staging area has been located on the Grading and Erosion Control Plan, but the Contractor and ECP Administrator should determine together the best location and it should be installed per the details provided in Appendix B. Implementation Phase (I.C.3.c.3) - Phase I Inspection Interval (I.D.6 and I.D.7) – Every 14 days and within 24 hours following precipitation or snow melt St. Elizabeth Ann Seton Catholic Church Expansion Erosion & Dust Control Report Colorado Civil Group, Inc. 11 4.2.3 Silt Fence (Structural - I.C.3.c.1) Silt Fence should be installed prior to construction and must be installed before any soil disturbance occurs. Silt Fence should be installed per the construction plan details and must continually be monitored for effectiveness. Silt Fence does not need to be installed around the entire construction site; it only needs to be installed where surface runoff might transport sediment or other materials off-site. Silt Fence will be installed where indicated on the Grading and Erosion Control Plan. Additional silt fence should installed if determined necessary by the ECP Administrator. Implementation Phase (I.C.3.c.3) – Phase I Inspection Interval (I.D.6 and I.D.7) – Every 14 days and within 24 hours following precipitation or snow melt 4.2.4 Straw Waddles (Structural - I.C.3.c.1) Straw Waddles will be used around the existing detention pond outlet structure, proposed swales, and proposed storm sewer during the construction process to mitigate the transportation of sediment. Proper installation is the most important aspect of straw waddles. These protection measures function poorly if not installed correctly, so the construction details provided with the plans must be followed. Straw Waddles will be installed where indicated on the Grading and Erosion Control Plan. Implementation Phase (I.C.3.c.3) – Phase I Inspection Interval (I.D.6 and I.D.7) – Every 14 days and within 24 hours following precipitation or snow melt 4.2.5 Concrete Washout Area (Structural - I.C.3.c.7) As construction begins and concrete is delivered to the site via concrete trucks, a concrete washout area is needed along with a vehicle tracking control pad. If concrete is generated on site via a batch plant, it will be located near the stabilized staging area. The concrete washout should be in a designated area with signs clearly marking its location. Prior to exiting the site, any vehicle with concrete debris must wash the concrete off at the washout area. The location of the washout area must ensure washoff does not enter the storm drain system. As needed, the area will be cleared of any concrete debris which will be disposed of properly. The Concrete Washout will be installed where St. Elizabeth Ann Seton Catholic Church Expansion Erosion & Dust Control Report Colorado Civil Group, Inc. 12 indicated on the Grading and Erosion Control Plan and should be installed per the details provided in Appendix B. Implementation Phase (I.C.3.c.3) – Phase I Inspection Interval (I.D.6 and I.D.7) – Every 14 days and within 24 hours following precipitation or snow melt 4.3 Permanent BMPs 4.3.1 Surface Roughening/Mulching and Re-Seeding (Non-Structural - I.C.3.c.2) Once a construction site is reaching completion, areas of bare ground that have not already been protected with surface roughening techniques, landscaping, mulching, or re-seeding must receive this permanent treatment. This permanent BMP is critical to preventing soil erosion during precipitation events and achieving final stabilization. Surface roughening is expected once the final grades are established. Implementation Phase (I.C.3.c.3) - Phase IV Inspection Interval (I.D.6 and I.D.7) – Every 14 days and within 24 hours following precipitation or snow melt 4.3.2 Rain Garden A rain garden utilizes bioretention to reduce the transportation of pollutants to downstream receiving waters through sedimentation, filtering, adsorption, evapotranspiration, and biological uptake of constituents. The UDFCD provides guidelines and tools for the design of rain gardens, which have been used for the SEAS project. The sizing calculations` have been included in Final Drainage Report. The Rain Garden will be installed where indicated on the Grading and Erosion Control Plan. Implementation Phase (I.C.3.c.3) - Phase II Inspection Interval (I.D.6 and I.D.7) – Every 14 days and within 24 hours following precipitation or snow melt 5 BMPs for Material Handling and Spill Prevention (I.C.3.c.4) Section 3 of this report identifies possible pollutant sources that can be expected with the construction of the SEAS project. Material handling and spill prevention information must be distributed to all contractors and subcontractors working at the construction site. This St. Elizabeth Ann Seton Catholic Church Expansion Erosion & Dust Control Report Colorado Civil Group, Inc. 13 information, along with response and notification procedures, must be in place prior to construction and must be administered by the site superintendent. Contractors should be instructed to notify the site superintendent and ECP Administrator immediately if any spill occurs. The ECP Administrator will determine the nature of the spill and, if necessary, contact the Colorado Department of Public Health and Environment (24- hour spill reporting line – 877-518-5608), downstream water users, and any other agency or jurisdiction deemed necessary. For hazardous material or liquid storage, concrete truck washouts, and fueling and maintenance locations, proper instructions for clean-up procedures should be posted and spill kit locations should be identified. Information on absorbents should also be made available at all liquid storage locations and fueling locations, and proper disposal locations for used absorbents should be provided. 6 Final Stabilization and Ultimate Stormwater Management (I.C.4) Final stabilization is the last step in the construction process and begins after major construction activities have ended. The site superintendent should inspect the site one final time to ensure that all BMPs will function correctly in a precipitation event. If any unpaved areas exist, all exposed or bare soil that has not previously been treated must be identified and the appropriate procedure implemented to achieve final stabilization. This includes re- seeding of disturbed areas with an approved seed mix, soil preparation, soil amendments, where necessary, and soil stabilization methods such as crimped straw, hydro-mulch, or rolled erosion control products. Two seed mixes are expected, one for general disturbed areas and the second for the rain garden. The two mixes are shown below. Final stabilization is achieved once all ground disturbing activities have been completed and uniform vegetative cover has been established with an individual plant density of at least 70% of pre-disturbance levels. Ultimate stormwater management is achieved through the use of temporary BMPs until final site stabilization is achieved and the continued maintenance and operation of the permanent BMPs installed on-site. 7 Construction Site Inspection and Maintenance (I.C.5, I.D.6, I.D.7) Standard construction site inspection and maintenance schedules were identified in Section 4 for each of the anticipated temporary and permanent BMPs to be installed on-site. Part I.D.6.a of the Stormwater Construction Permit requires that a thorough inspection of the stormwater management system be performed and documented at least every 14 days and within 24 hours following any precipitation or snowmelt event that causes surface erosion. St. Elizabeth Ann Seton Catholic Church Expansion Erosion & Dust Control Report Colorado Civil Group, Inc. 14 More frequent inspections may be necessary and should be performed at the request of the ECP Administrator. This report can be modified to provide any additional pollution controls or meet increased inspection needs, if deemed necessary. Standard site inspection procedures that must be followed by the site superintendent are as follows: • The perimeter of the construction site must be inspected to ensure that no unintended stormwater discharge is occurring. • All perimeter temporary and permanent BMPs must be inspected to ensure they are functioning correctly and are in a condition that can reasonably be expected to function appropriately in a future precipitation event. • Any disturbed areas should be inspected to determine if pollution is entering the stormwater system and if any further controls should be implemented to better protect the stormwater system. • All areas where construction site material is stored should be inspected for compliance with this report. Areas should be checked for any spills that may have occurred without being reported and should also be evaluated to determine if additional control measures should be installed to prevent contamination. If necessary, these areas should be checked to ensure that they are covered or protected from precipitation or wind events. • All interior temporary and permanent BMPs should be inspected for performance and should be replaced if found to be deficient. • The site superintendent should monitor the construction activities occurring on-site and install approved controls as necessary even if those controls are not mentioned in this report. • A log of each inspection should be kept on-site at all times and should be made available upon request to any governing agency or jurisdiction, the Environmental Protection Agency, or the Colorado Department of Public Health and Environment. A log book may be kept for use in tracking other items related to the ECP such as those listed below. Additional information such as dated photographs, field notebooks, drawings and maps, and the items below, etc. can also be included where appropriate. • BMP operation and maintenance St. Elizabeth Ann Seton Catholic Church Expansion Erosion & Dust Control Report Colorado Civil Group, Inc. 15 • Stormwater contamination • Contacts with suppliers • Notes on the need for and performance of preventive maintenance and other repairs • Implementation of specific items in the ECP • Training events (given or attended) • Events involving materials handling and storage • Contacts with regulatory agencies and personnel • Notes of employee activities, contact, notifications, etc. This information can also be found in Part I.D.6 of the Construction Permit and should be referenced often to ensure adequate inspection practices are followed. St. Elizabeth Ann Seton Catholic Church Expansion Erosion & Dust Control Report A Appendix A: Soils Information Drainage Class—Larimer County Area, Colorado (DRAINAGE CLASS) Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 6/24/2017 Page 1 of 3 4484250 4484290 4484330 4484370 4484410 4484450 4484490 4484250 4484290 4484330 4484370 4484410 4484450 4484490 495030 495070 495110 495150 495190 495230 495270 495310 495350 495390 495030 495070 495110 495150 495190 495230 495270 495310 495350 495390 40° 30' 40'' N 105° 3' 31'' W 40° 30' 40'' N 105° 3' 15'' W 40° 30' 32'' N 105° 3' 31'' W 40° 30' 32'' N 105° 3' 15'' W N Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 13N WGS84 0 50 100 200 300 Feet 0 25 50 100 150 Meters Map Scale: 1:1,700 if printed on A landscape (11" x 8.5") sheet. Soil Map may not be valid at this scale. MAP LEGEND MAP INFORMATION Area of Interest (AOI) Area of Interest (AOI) Soils Soil Rating Polygons Excessively drained Somewhat excessively drained Well drained Moderately well drained Somewhat poorly drained Poorly drained Very poorly drained Subaqueous Not rated or not available Soil Rating Lines Excessively drained Somewhat excessively drained Well drained Moderately well drained Somewhat poorly drained Poorly drained Very poorly drained Subaqueous Not rated or not available Soil Rating Points Excessively drained Somewhat excessively drained Well drained Moderately well drained Somewhat poorly drained Poorly drained Very poorly drained Subaqueous 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: Coordinate System: Web Mercator (EPSG:3857) Drainage Class Drainage Class— Summary by Map Unit — Larimer County Area, Colorado (CO644) Map unit symbol Map unit name Rating Acres in AOI Percent of AOI 27 Cushman fine sandy loam, 3 to 9 percent slopes Well drained 3.1 26.6% 35 Fort Collins loam, 0 to 3 percent slopes Well drained 0.3 2.1% 55 Kim loam, 5 to 9 percent slopes Well drained 0.4 3.4% 103 Stoneham loam, 5 to 9 percent slopes Well drained 6.1 52.3% 119 Wiley silt loam, 3 to 5 percent slopes Well drained 1.8 15.6% Totals for Area of Interest 11.7 100.0% Description "Drainage class (natural)" refers to the frequency and duration of wet periods under conditions similar to those under which the soil formed. Alterations of the water regime by human activities, either through drainage or irrigation, are not a consideration unless they have significantly changed the morphology of the soil. Seven classes of natural soil drainage are recognized-excessively drained, somewhat excessively drained, well drained, moderately well drained, somewhat poorly drained, poorly drained, and very poorly drained. These classes are defined in the "Soil Survey Manual." Rating Options Aggregation Method: Dominant Condition Component Percent Cutoff: None Specified Tie-break Rule: Higher Drainage Class—Larimer County Area, Colorado DRAINAGE CLASS Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 6/24/2017 Page 3 of 3 Hydrologic Soil Group—Larimer County Area, Colorado (HYDROLOGIC SOIL GROUP) Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 6/24/2017 Page 1 of 4 4484250 4484290 4484330 4484370 4484410 4484450 4484490 4484250 4484290 4484330 4484370 4484410 4484450 4484490 495030 495070 495110 495150 495190 495230 495270 495310 495350 495390 495030 495070 495110 495150 495190 495230 495270 495310 495350 495390 40° 30' 40'' N 105° 3' 31'' W 40° 30' 40'' N 105° 3' 15'' W 40° 30' 32'' N 105° 3' 31'' W 40° 30' 32'' N 105° 3' 15'' W N Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 13N WGS84 0 50 100 200 300 Feet 0 25 50 100 150 Meters Map Scale: 1:1,700 if printed on A landscape (11" x 8.5") sheet. Soil Map may not be valid at this scale. 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: 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 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 27 Cushman fine sandy loam, 3 to 9 percent slopes C 3.1 26.6% 35 Fort Collins loam, 0 to 3 percent slopes C 0.3 2.1% 55 Kim loam, 5 to 9 percent slopes B 0.4 3.4% 103 Stoneham loam, 5 to 9 percent slopes B 6.1 52.3% 119 Wiley silt loam, 3 to 5 percent slopes B 1.8 15.6% Totals for Area of Interest 11.7 100.0% Hydrologic Soil Group—Larimer County Area, Colorado HYDROLOGIC SOIL GROUP Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 6/24/2017 Page 3 of 4 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 Tie-break Rule: Higher Hydrologic Soil Group—Larimer County Area, Colorado HYDROLOGIC SOIL GROUP Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 6/24/2017 Page 4 of 4 Wind Erodibility Group—Larimer County Area, Colorado (WIND ERODIBILITY GROUP) Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 6/24/2017 Page 1 of 3 4484250 4484290 4484330 4484370 4484410 4484450 4484490 4484250 4484290 4484330 4484370 4484410 4484450 4484490 495030 495070 495110 495150 495190 495230 495270 495310 495350 495390 495030 495070 495110 495150 495190 495230 495270 495310 495350 495390 40° 30' 40'' N 105° 3' 31'' W 40° 30' 40'' N 105° 3' 15'' W 40° 30' 32'' N 105° 3' 31'' W 40° 30' 32'' N 105° 3' 15'' W N Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 13N WGS84 0 50 100 200 300 Feet 0 25 50 100 150 Meters Map Scale: 1:1,700 if printed on A landscape (11" x 8.5") sheet. Soil Map may not be valid at this scale. MAP LEGEND MAP INFORMATION Area of Interest (AOI) Area of Interest (AOI) Soils Soil Rating Polygons 1 2 3 4 4L 5 6 7 8 Not rated or not available Soil Rating Lines 1 2 3 4 4L 5 6 7 8 Not rated or not available Soil Rating Points 1 2 3 4 4L 5 6 7 8 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: Coordinate System: Web Mercator (EPSG:3857) Wind Erodibility Group Wind Erodibility Group— Summary by Map Unit — Larimer County Area, Colorado (CO644) Map unit symbol Map unit name Rating Acres in AOI Percent of AOI 27 Cushman fine sandy loam, 3 to 9 percent slopes 3 3.1 26.6% 35 Fort Collins loam, 0 to 3 percent slopes 5 0.3 2.1% 55 Kim loam, 5 to 9 percent slopes 4L 0.4 3.4% 103 Stoneham loam, 5 to 9 percent slopes 6 6.1 52.3% 119 Wiley silt loam, 3 to 5 percent slopes 4L 1.8 15.6% Totals for Area of Interest 11.7 100.0% Description A wind erodibility group (WEG) consists of soils that have similar properties affecting their susceptibility to wind erosion in cultivated areas. The soils assigned to group 1 are the most susceptible to wind erosion, and those assigned to group 8 are the least susceptible. Rating Options Aggregation Method: Dominant Condition Component Percent Cutoff: None Specified Tie-break Rule: Lower Wind Erodibility Group—Larimer County Area, Colorado WIND ERODIBILITY GROUP Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 6/24/2017 Page 3 of 3 Wind Erodibility Index—Larimer County Area, Colorado (WIND ERODIBILITY INDEX) Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 6/24/2017 Page 1 of 3 4484250 4484290 4484330 4484370 4484410 4484450 4484490 4484250 4484290 4484330 4484370 4484410 4484450 4484490 495030 495070 495110 495150 495190 495230 495270 495310 495350 495390 495030 495070 495110 495150 495190 495230 495270 495310 495350 495390 40° 30' 40'' N 105° 3' 31'' W 40° 30' 40'' N 105° 3' 15'' W 40° 30' 32'' N 105° 3' 31'' W 40° 30' 32'' N 105° 3' 15'' W N Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 13N WGS84 0 50 100 200 300 Feet 0 25 50 100 150 Meters Map Scale: 1:1,700 if printed on A landscape (11" x 8.5") sheet. Soil Map may not be valid at this scale. MAP LEGEND MAP INFORMATION Area of Interest (AOI) Area of Interest (AOI) Soils Soil Rating Polygons 0 38 48 56 86 134 160 180 220 250 310 Not rated or not available Soil Rating Lines 0 38 48 56 86 134 160 180 220 250 310 Not rated or not available Soil Rating Points 0 38 48 56 86 134 160 180 220 250 310 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 Wind Erodibility Index Wind Erodibility Index— Summary by Map Unit — Larimer County Area, Colorado (CO644) Map unit symbol Map unit name Rating (tons per acre per year) Acres in AOI Percent of AOI 27 Cushman fine sandy loam, 3 to 9 percent slopes 86 3.1 26.6% 35 Fort Collins loam, 0 to 3 percent slopes 56 0.3 2.1% 55 Kim loam, 5 to 9 percent slopes 86 0.4 3.4% 103 Stoneham loam, 5 to 9 percent slopes 48 6.1 52.3% 119 Wiley silt loam, 3 to 5 percent slopes 86 1.8 15.6% Totals for Area of Interest 11.7 100.0% Description The wind erodibility index is a numerical value indicating the susceptibility of soil to wind erosion, or the tons per acre per year that can be expected to be lost to wind erosion. There is a close correlation between wind erosion and the texture of the surface layer, the size and durability of surface clods, rock fragments, organic matter, and a calcareous reaction. Soil moisture and frozen soil layers also influence wind erosion. Rating Options Units of Measure: tons per acre per year Aggregation Method: Dominant Condition Component Percent Cutoff: None Specified Tie-break Rule: Higher Wind Erodibility Index—Larimer County Area, Colorado WIND ERODIBILITY INDEX Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 6/24/2017 Page 3 of 3 St. Elizabeth Ann Seton Catholic Church Expansion Erosion & Dust Control Report B Appendix B: Grading Plan and Construction Details 8'' SS 8'' SS 8'' SS 1. THIS GRADING AND EROSION CONTROL PLAN CONSIDERS EROSION CONTROL DURING CONSTRUCTION ACTIVITIES. 2. THE CONTRACTOR SHALL HAVE ON-SITE AT ALL TIMES THE STORMWATER MANAGEMENT PLAN, AND FOLLOW ALL RECOMMENDATIONS CONTAINED WITHIN. 3. THE CONTRACTOR SHALL RECORD CHANGES TO THE SITE'S STORMWATER MANAGEMENT PLAN AS CONSTRUCTION ACTIVITIES DICTATE. 4. THE CONTRACTOR SHALL SECURE A STAGING AREA IN COORDINATION WITH THE OWNER, AND SHALL INCLUDE A SOLID WASTE DISPOSAL AREA, PORT-O-LETS, MATERIAL STORAGE AND A DEDICATED RE-FUELING AND MAINTENANCE AREA. 5. THE CONTRACTOR CAN CHOOSE BETWEEN SILT FENCE AND SEDIMENT CONTROL LOGS WHERE INDICATED ON THE PLANS. 6. THE CONTRACTOR SHALL ESTABLISH ONE LOCATION FOR A CONCRETE TRUCK WASHOUT. 7. GRADING CATCH SLOPES SHALL NOT EXCEED 4:1 UNLESS OTHERWISE NOTED ON TEH PLANS. 8. IF POSSIBLE, AREAS ADJACENT TO THE CHURCH EXPANSION THAT DO NOT RECEIVE CONCRETE PAVING, THE FINISHED GRADE SHALL FALL A MINIMUM OF ONE FOOT IN THE FIRST 10 FEET FROM BUILDING OR AT A GRADE OF 10%. 9. PROPOSED EMERGENCY ACCESS ROUTE SHALL BE CONSTRUCTION OF CDOT CLASS D CONCRETE (4500 PSI), AND SHALL BE A MINIMUM OF 8" THICK OR AS DIRECTED BY A GEOTECHNICAL ENGINEER. 10. CONTRACTOR SHALL PERFORM A PROOF-ROLL OF THE SUBGRADE BELOW THE PROPOSED EMERGENCY ACCESS IN THE PRESENCE OF A GEOTECHNICAL ENGINEER. 11. THE LONGITUDINAL SLOPE OF THE EMERGENCY ACCESS DRIVE SHALL NOT EXCEED 10% IN ANY LOCATION. 12. THE CROSS-SLOPE OF THE EMERGENCY ACCESS DRIVE SHALL BE 2% FALLING AWAY FROM THE CHURCH AND TOWARD THE EXISTING DETENTION POND. 13. AN EMERGENCY OVERFLOW SECTION IS PROVIDED ALONG THE PROPOSED EMERGENCY ACCESS DRIVE, IN THE EVENT THE 12-INCH CULVERT IS PLUGGED. THIS OVERFLOW SECTION IS MORE THAN 12 INCHES BELOW GRADING ADJACENT TO BASEMENT OF CHURCH. PROPOSED EXPANSION EXISTING BUILDING EXISTING ASPHALT EXISTING CONCRETE PROPOSED CONCRETE EXISTING LANDSCAPING EXISTING GAS LINE EXISTING FIBER OPTIC EXISTING STORM DRAIN EXISTING WATER EXISTING SANITARY EXISTING TELEPHONE PROPOSED EXISTING PR. EX. BY SEPARATE DOCUMENT EMERGENCY ACCESS ESM BSD EAE DATE DESCRIPTION REVISIONS 0031.0012.00_GRADING SEPTEMBER 13, 2017 OF DATE: 1413 W. 29TH STREET Vehicle Tracking Control (VTC) SM-4 November 2010 Urban Drainage and Flood Control District VTC-3 Urban Storm Drainage Criteria Manual Volume 3 SM-4 Vehicle Tracking Control (VTC) VTC-4 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Vehicle Tracking Control (VTC) SM-4 November 2010 Urban Drainage and Flood Control District VTC-5 Urban Storm Drainage Criteria Manual Volume 3 SM-4 Vehicle Tracking Control (VTC) VTC-6 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Stabilized Staging Area (SSA) SM-6 November 2010 Urban Drainage and Flood Control District SSA-3 Urban Storm Drainage Criteria Manual Volume 3 SM-6 Stabilized Staging Area (SSA) SSA-4 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Sediment Control Log (SCL) SC-2 November 2015 Urban Drainage and Flood Control District SCL-3 Urban Storm Drainage Criteria Manual Volume 3 SC-2 Sediment Control Log (SCL) SCL-4 Urban Drainage and Flood Control District November 2015 Urban Storm Drainage Criteria Manual Volume 3 Sediment Control Log (SCL) SC-2 November 2015 Urban Drainage and Flood Control District SCL-5 Urban Storm Drainage Criteria Manual Volume 3 SC-2 Sediment Control Log (SCL) SCL-6 Urban Drainage and Flood Control District November 2015 Urban Storm Drainage Criteria Manual Volume 3 Concrete Washout Area (CWA) MM-1 November 2010 Urban Drainage and Flood Control District CWA-3 Urban Storm Drainage Criteria Manual Volume 3 MM-1 Concrete Washout Area (CWA) CWA-4 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 COLORADO CIVIL GROUP, INC. • 5110 Granite St., Unit D • Loveland, Colorado 80538 • 970-278-0029 LOVELAND, COLORADO 80538 (970) 278-0029 CCGCOLORADO CIVIL GROUP, INC. ENGINEERING CONSULTANTS SHEET: 1" = 40' SCALE: 0031.0012.00 JOB NO: DAH CHECKED: DAH DESIGNED: FILE NAME: 0" 1" BAR IS ONE INCH ON ORIGINAL DRAWING 1" = 40' 0 40 80 scale feet CALL THE UTILITY NOTIFICATION CENTER OF COLORADO 3 DAYS BEFORE YOU DIG 811 OR 1-800-922-1987 www.UNCC.org Mr. Michael D. DiTullio, Manager Mr. Terry Farrill, P.E., District Engineer Date Date All changes, addendums, additions, deletions and modifications to these drawings must be approved, in writing, by the Fort Collins-Loveland Water District and the South Fort Collins Sanitation District. SOUTH FORT COLLINS SANITATION DISTRICT NOTES: 1. SUB-GRADE BELOW ALL PAVEMENT SECTIONS SHALL BE SCARIFIED TO A MINIMUM DEPTH OF 12" , ADJUSTED IN MOISTURE CONTENT (+ 2%) AND COMPACTED TO AT LEAST 95% OF THE MATERIAL'S MAXIMUM STANDARD PROCTOR DRY DENSITY AS DETERMINED IN ACCORDANCE WITH ASTM SPECIFICATION D698. CONTRACTOR SHALL PROOF-ROLL COMPACTED SUB-GRADE IN THE PRESENCE OF A GEOTECHNICAL ENGINEER OR CITY INSPECTOR. 2. IF SUB-GRADE MATERIAL IS UNSUITABLE (EXHIBITS PUMPING DURING PROOF-ROLL) IT SHALL EITHER BE RECONDITIONED OR REPLACED WITH SUITABLE ON-SITE MATERIALS. IF CONTRACTOR CHOOSES, STRUCTURAL FILL MAY BE IMPORTED, AT NO EXTRA COST TO OWNER, AND SHALL BE GRADED SIMILARLY TO CDOT CLASS 5 OR 6 AGGREGATE BASE. CONTRACTOR SHALL PROOF-ROLL ANY RE-WORKED SUB-GRADE PRIOR TO PLACEMENT OF AGGREGATE BASE COURSE. 3. IF CALLED FOR, AGGREGATE BASE COURSE SHALL BE ADJUSTED IN MOISTURE CONTENT (+ 2%) AND COMPACTED TO ACHIEVE A MINIMUM OF 95% OF THE MATERIAL'S MAXIMUM STANDARD PROCTOR DRY DENSITY AS DETERMINED IN ACCORDANCE WITH ASTM SPECIFICATION D698. CDOT CLASS D CONCRETE (4500 PSI) RECONDITIONED SUBGRADE 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: 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 Survey Area Data: Version 11, Sep 23, 2016 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. Wind Erodibility Index—Larimer County Area, Colorado (WIND ERODIBILITY INDEX) Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 6/24/2017 Page 2 of 3 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 Survey Area Data: Version 11, Sep 23, 2016 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. Wind Erodibility Group—Larimer County Area, Colorado (WIND ERODIBILITY GROUP) Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 6/24/2017 Page 2 of 3 of the version date(s) listed below. Soil Survey Area: Larimer County Area, Colorado Survey Area Data: Version 11, Sep 23, 2016 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 (HYDROLOGIC SOIL GROUP) Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 6/24/2017 Page 2 of 4 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 Survey Area Data: Version 11, Sep 23, 2016 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. Drainage Class—Larimer County Area, Colorado (DRAINAGE CLASS) Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 6/24/2017 Page 2 of 3