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HomeMy WebLinkAboutBDR FOUR-PLEX, 621 S. MELDRUM ST. - FDP130002 - SUBMITTAL DOCUMENTS - ROUND 1 - DRAINAGE REPORT (3)February 20, 2013 EROSION CONTROL REPORT BIG DEAL FOUR PLEX Fort Collins, Colorado Prepared for: Big Deal Real Estate Inc. 2519 Ridge Creek Road Fort Collins, CO 80528 Prepared by: 200 South College Avenue, Suite 10 Fort Collins, Colorado 80524 Phone: 970.221.4158 Fax: 970.221.4159 www.northernengineering.com Project Number: 876-001 3 This Report is consciously provided as a PDF. Please consider the environment before printing this document in its entirety. When a hard copy is absolutely necessary, we recommend double-sided printing. February 20, 2013 City of Fort Collins Stormwater Utility 700 Wood Street Fort Collins, CO 80521 RE: Erosion Control Report for Big Deal Four Plex Dear Staff, Northern Engineering Services, Inc. is pleased to submit this Erosion Control Report (ECR) for Big Deal Four Plex. The objectives of this Erosion Control Report (ECR) are to identify potential sources of pollution resulting from the construction activity associated with the site improvements described herein and recommend Best Management Practices (BMPs) that can be used to reduce or eliminate the likelihood of these pollutants entering stormwater discharges from the site. If you should have any questions or comments as you review this report, please feel free to contact us at your convenience. Sincerely, NORTHERN ENGINEERING SERVICES, INC. Herman Feissner, P.E. Project Engineer Big Deal Four Plex Stormwater Management Plan TABLE OF CONTENTS Vicinity Map 1.0 General Requirements..............................................................................................1 1.1 Objectives...............................................................................................................1 1.2 Definitions ..............................................................................................................1 2.0 Narrative Site Description .........................................................................................2 2.1 Existing Site Description ............................................................................................2 2.2 Wind and Rainfall Erodibility .....................................................................................2 2.3 Nature of Construction Activity ...................................................................................2 2.4 Sequence of Major Activities ......................................................................................2 2.5 Site Disturbance ......................................................................................................2 2.6 Existing Data...........................................................................................................3 2.7 Potential Pollution Sources ........................................................................................3 2.8 Receiving Waters .....................................................................................................3 Figure 1 – Existing Drainage and Irrigation Infrastructure .....................................................................4 3.0 Stormwater Management Controls .............................................................................5 3.1 Best Management Practices (BMPs) for Stormwater Pollution Prevention ..........................5 3.2 Structural Practices for Erosion and Sediment Control ....................................................5 3.3 Non-Structural Practices for Erosion and Sediment Control .............................................7 3.4 Phased BMP Installation ...........................................................................................7 3.5 Material Handling and Spill Prevention ........................................................................8 3.6 Waste Management and Disposal ...............................................................................8 4.0 Final Stabilization and Long-Term Stormwater Management ....................................... 10 4.1 Final Stabilization .................................................................................................. 10 4.2 Long-Term Stormwater Management ......................................................................... 10 5.0 Inspection and Maintenance ................................................................................... 11 4.3 BMP Inspection ..................................................................................................... 11 4.4 BMP Maintenance ................................................................................................. 11 References 12 Big Deal Four Plex Stormwater Management Plan LIST OF TABLES: Table 1 – Construction Schedule ........................................................................................... 5 APPENDICES: APPENDIX A – Grading and Erosion Control Plan APPENDIX B – Erosion Control Details APPENDIX C – Landscape Plan Big Deal Four Plex Erosion Control Report 1 1.0 General Requirements 1.1 Objectives The objectives of this Erosion Control Report (ECR) are to identify potential sources of pollution resulting from construction activity associated with the site improvements described herein and recommend Best Management Practices (BMPs) that can be used to reduce the pollutants in stormwater discharges from the site. The ECR must be completed and implemented at the time the project breaks ground and revised as necessary, while construction proceeds, to accurately reflect the conditions and practices at the site. 1.2 Definitions Best Management Practices (BMPs) – BMPs encompass a wide range of erosion and sediment control practices, both structural and non-structural in nature, which are intended to reduce or eliminate potential water quality impacts from construction site stormwater runoff. Erosion Control BMPs – These practices are intended to prevent the erosion of soil. A few common examples include: minimizing the amount of disturbed area through phasing, temporary stabilization and preserving existing vegetation. Sediment Control BMPs – These practices are designed to remove sediment from runoff. Examples of few include: straw wattles, silt fence and inlet protection. Non-structural BMPs – These BMPs prevent or limit the entry of pollutants into stormwater at their source through operational or managerial techniques. Some examples include: the preservation of natural vegetation, preventive maintenance and spill response procedures. Structural BMPs – Structural practices are designed to control on-site erosion and prevent sediment from migrating within the project site as well as off-site during construction. This type of BMP includes physical processes ranging from diversion structures to inlet protection and silt fence. Big Deal Four Plex Erosion Control Report 2 2.0 Narrative Site Description 2.1 Existing Site Description The project site is located in the Northeast Quarter of Section 14, Township 7 North, Range 69 West of the 6th Principal Meridian, City of Fort Collins, County of Larimer, State of Colorado. More specifically, the project is located at 621 South Meldrum Street. The project site is bordered to the north and south by single-family homes; to the east by Meldrum Street (100' Right-of-Way); and to the west by an existing alley (20' Right-of-Way). The existing site improvements include: one single-family home which fronts to Meldrum Street, a detached garage and a small shed. The existing ground cover consists of several mature trees, grass, weeds and bare soil. 2.2 Wind and Rainfall Erodibility The site is located within a moderate risk Erodibility Zone per the City of Fort Collins Wind Erodibility Map. According to the Natural Resources Conservation Service website - www.websoilsurvey.nrcs.usda.gov, the applicable soil erosion factor (K), which indicates the susceptibility of a soil to sheet and rill erosion, is 0.28. This value is indicative of soils moderately susceptible to rainfall erosion. Impervious area (i.e., roof area, concrete walks and asphalt parking area) and landscaping will permanently stabilize the areas disturbed by the proposed construction activity; therefore, the likelihood of erosion and sediment problems occurring on-site is minimal. Most of the proposed landscaped area is situated between the proposed structure and asphalt parking area). During the interim period, in which the disturbed areas are open, the BMPs described herein were selected to prevent erosion and limit sediment migration. 2.3 Nature of Construction Activity The proposed Big Deal Four Plex project will include a two-story building with four units and a footprint of approximately 2570 sq. ft. The other major proposed improvements include: a new asphalt parking area and updated landscaping. 2.4 Sequence of Major Activities To complete the project, many basic construction activities will take place. The project will begin by removing the existing site improvements such as the existing single-family home. The installation, removal/replacement, or re-routing of existing utilities (e.g., electric, gas, sanitary sewer, domestic water and storm drain) will occur next. While building foundations are being constructed, concrete barrier curbs will be installed around the parking area. The asphalt paving in the parking area will likely follow completion of exterior construction. The fine grading of the landscaped areas and the installation of retaining walls and landscaping will mark the completion of the construction activities. 2.5 Site Disturbance The project site is approximately 0.22 acre in size. The area that will be disturbed by construction activity is 0.22 acre. Big Deal Four Plex Erosion Control Report 3 2.6 Existing Data In order to complete the associated construction plans, a topographical survey of the site was completed. The survey consisted of field measurements made by Northern Engineering Services, Inc. in November 2012. The site-specific subsurface exploration was performed by Soilogic, Inc. Detailed results from this work are contained in the Geotechnical Subsurface Exploration Proposed Multi-Family 4-plex Residence 621 South Meldrum Street Fort Collins, Colorado (Soilogic Project # 12-1094) dated November 28, 2012. 2.7 Potential Pollution Sources As is typical with most construction sites, there are a number of potential pollution sources which could affect water quality. It is not possible for this report to identify all the materials that will be used or stored on the construction site. It is the sole responsibility of the contractor to identify and properly handle materials that are potential pollution sources. The following are some common examples of potential pollution sources: x Exposed and stored soils x Vehicle tracking of sediments x Management of contaminated soils x Outdoor storage of building materials, fertilizers, chemicals, etc. x Vehicle and equipment maintenance and fueling x Significant dust or particulate generating processes x Routine maintenance activities involving fertilizers, pesticides, detergents, fuels, solvents, oils, etc. x On-site waste disposal practices (waste piles, dumpsters, etc.) x Concrete truck/equipment washing, including the concrete truck chute and associated fixtures and equipment x Dedicated asphalt and concrete batch plants x Non-industrial waste sources such as worker trash and portable toilets x Other areas or procedures where potential spills can occur Management of Contaminated Soils: We are not aware of on-site contaminated soils. However, the contractor should conduct a thorough, pre-construction environmental site assessment. If contaminated soils are discovered, the contractor will identify appropriate practices and procedures for the specific contaminants discovered on-site. Loading and Unloading Operations: During site demolition, material loading and unloading will occur on-site. As site development and building construction progresses, space constraints will limit the number of on-site locations for loading and unloading activities to the parking garage drive aisle entrance and Bluebell Street. The contractor will be responsible for the proper handling and management of pollution sources during loading and unloading operations. Dedicated Asphalt and Concrete Batch Plants: Neither a dedicated asphalt or concrete batch plant will be constructed on-site. 2.8 Receiving Waters The excess stormwater runoff from the project area generally sheet flows to existing stormwater Big Deal Four Plex Erosion Control Report 4 infrastructure along well established drainage paths. More specifically, the excess runoff from disturbed area on the east side of the project site enters the curb and gutter in Meldrum Street and flows north to an existing combination inlet (refer to Figure 1). This inlet is connected to an existing storm drain system that outfalls into the Udall Natural Area. Stormwater flows from downtown and nearby neighborhood storm drains flow into this system, which drains into a series of ponds (i.e., Udall Natural Area), before entering the Poudre River. Excess runoff from west portion of the project site will flow into the Arthur Ditch. Figure 1 – Existing Drainage and Irrigation Infrastructure Project Site Big Deal Four Plex Erosion Control Report 5 3.0 Stormwater Management Controls 3.1 Best Management Practices (BMPs) for Stormwater Pollution Prevention Best Management Practices (BMPs) are loosely defined as a method, activity, maintenance procedure or other management practice for reducing the amount of pollution entering a water body. The term originated from rules and regulations in Section 208 of the Clean Water Act. Starting with mobilization, and throughout the entire construction of the buildings, erosion control devices should be installed and maintained to minimize pollutant migration. The BMPs may be installed or implemented in phases, or not at all, depending on actual conditions encountered at the site. It is the responsibility of the contractor to make the determination as to what practices should be employed and when. In the event that a review agency deems BMPs to be insufficient, it shall be the responsibility of the contractor to implement modifications as directed. Table 1 (see below) depicts the construction sequence and associated BMPs. The Erosion Control Static Site Plan (Refer to sheet C6.00 in Appendix A) illustrates the assumed location for each of the BMPs. Details for recommended BMPs are included in Appendix A. These details should be used for additional information on installation and maintenance of BMPs described herein. 3.2 Structural Practices for Erosion and Sediment Control Structural BMPs are physical devices that prevent or minimize water quality impacts associated with construction site stormwater runoff. These devices can be temporary or permanent, and the installation of individual components will vary depending on the stage of construction. Again, the final determination for which BMPs will be installed, where they will be located and when they will be installed shall be made by the contractor. Silt Fencing (Phases I - IV) Silt fencing shall be provided to prevent migration of sediment off-site into the public right- of-way and onto neighboring properties. All silt fencing shall be installed prior to any land disturbing activity (i.e., stockpiling, stripping, grading, excavation, earthwork activities, etc.). The silt fence inspections should identify tears or holes in the material as well as check for slumping fence or undercut areas that allow flows to bypass the fencing. The damaged sections of fencing should be repaired or replaced. Sediment accumulations equal to or greater than six inches behind the silt fence should be removed to maintain BMP effectiveness. At a minimum, it is suggested that silt fencing shall be located along the north and south property lines of the disturbed area to prevent sediment from leaving the site and entering the neighboring properties. Additionally, silt fence should be installed along the east property. This section of silt fence should prevent sediment from entering the public Right- of-Way (ROW). Vehicle Tracking Control Pads (Phases I -IV) Vehicle tracking control pads shall be provided to minimize tracking of mud and sediment onto paved surfaces and neighboring roadways. All vehicle tracking control pads shall be installed prior to any land disturbing activity (e.g., stockpiling, stripping, grading, etc.). The vehicle tracking control pads should be located at any and all existing and future vehicle accesses being used during any of the construction phases. These locations will primarily be dictated by gates or openings in the temporary construction fencing. Big Deal Four Plex Erosion Control Report 6 Vehicle tracking pads should be inspected for degradation. The aggregate material should remain rough and be replaced if the area becomes clogged with water and/or excess sediment. Area Inlet Protection (Phases I - IV) The TenCate Mirafi Dandy Sack (or approved equal) area Inlet Filter (IF) should be installed in the existing area inlet located west of the project site in the alley. Inlet Protection (IP) should be placed around the two proposed Nyloplast 12" Standard Grates. Installing these BMPs before construction begins should prevent sediment from entering the proposed storm drain system as well as the existing storm drain system and the Arthur Ditch. The area inlet protection should be inspected regularly and maintained as necessary. It will be left to the discretion of the contractor as to when maintenance or replacement is necessary. The contractor is encouraged to follow the manufacturer recommendations. Sediment Control Log – aka “Straw Wattles” (Phases I - IV) A Sediment Control Log is a linear roll made of natural materials, such as straw, coconut fiber or other fibrous material trenched into the ground and anchored with a wooden stake. Sediment Control Logs can be used as perimeter control for stockpiles, as check dams in small drainage ways (e.g., swales) or on disturbed slopes to shorten flow lengths. If the wattles are weighted, they can be used as part of an Inlet Protection (IP) design. Sediment Control Logs should be inspected for excess sediment accumulation. The sediment should be removed prior to reaching half the height of the log. At a minimum, Sediment Control Logs should be used around soil stockpiles and for inlet protection in unpaved areas of the site. Straw wattles are proposed at the downstream end (or upstream end of the metal sidewalk culverts) of the north and south swales. Rock Socks (Phases I - IV) Rock Socks are proposed along the west curbline of Meldrum Street (i.e., at the downstream end of each metal sidewalk culvert) to reduce the velocity of water leaving the project site and introduce another opportunity for sediment removal. Rock Sock heights should allow for pools to develop upstream, creating minor backwaters to both reduce velocities and to allow sediment deposition. The rock socks should be spaced so that the top of each dam is equal in elevation to the toe of the next upstream check dam. Rock socks should be inspected regularly for gaps or holes which would allow water to pass through the structures untreated. The accumulated sediment should be removed and typically prior to the sediment depth reaching half the height of the check dam. At a minimum, rock socks should be installed at downstream end of each metal sidewalk culvert. Concrete Washout Area (Phases I - III) A concrete washout area may be provided on-site. The washout can be lined or unlined excavated pits in the ground, commercially manufactured prefabricated containers, or above the ground holding areas. The concrete washout must be located a minimum of 400 feet from any natural drainage way or body of water, and at least 1000 feet from any wells or drinking water sources. Washout areas should not be located in an area where shallow groundwater may be present. The contractor shall place a Vehicle Tracking Pad if the selected location for the Concrete Washout Area is detached from pavement. Clear signage identifying the concrete washout should also be provided. Big Deal Four Plex Erosion Control Report 7 The Concrete Washout Area should be inspected regularly. Particular attention should be paid to signage to ensure that the area is clearly marked. Confirmation that the washout is being used should also be noted to ensure that other undesignated areas of the site are not being used incorrectly as a concrete washout. Permanent/Established Vegetation (Phase IV) Permanent or established vegetation and landscaping is considered a permanent form of sediment and erosion control. Areas where the previous conditions apply will contain sufficient permanent BMPs such as sod or landscape material (e.g., smooth river rock/cobble and wood mulch). 3.3 Non-Structural Practices for Erosion and Sediment Control Non-Structural BMPs are practices or activities that are implemented to prevent erosion from occurring or limit its effects. These BMPs can be a practice resulting in physical changes to the site, such as mulching or slope stabilization. They can also result in behavioral changes on the site, such as changes to construction phasing to minimize exposure to weather elements, or increased employee awareness gained through training. Good Housekeeping Practices (Phases I -IV) Good housekeeping practices that will prevent pollution associated with solid, liquid, and hazardous construction-related materials and wastes should be implemented throughout the project. Examples of good housekeeping include providing an appropriate location for waste management containers, establishing proper building material staging areas, establishing proper equipment/vehicle fueling and maintenance practices. Street Sweeping (Phases I -IV) Street sweeping should be used to remove sediment that has been tracked onto adjacent roadways. Roadways should be inspected at least once a day, and sediment should be removed as needed. A check of the area inlet protection should be completed after sweeping to ensure nothing was displaced during sweeping operations. Street sweeping can reduce the sediment washed into the existing storm drain system. Street sweeping may be necessary on the existing hardscape areas which receive runoff from the disturbed areas. Saw Cutting Pollution Prevention (Phase II) The following protocol is recommended to prevent dust and slurry from asphalt and concrete saw cutting activities from migrating into the existing storm drain system. - Slurry and cuttings shall be vacuumed during cutting and surfacing operations - Slurry and cuttings shall not remain on permanent concrete or asphalt pavement overnight - Slurry and cuttings shall not drain to any natural or constructed drainage conveyance - Collected slurry and cuttings shall be disposed of in a manner that does not violate groundwater or surface water standards 3.4 Phased BMP Installation It is important to recognize the four (4) major Development Phases as defined by the State of Colorado’s Stormwater Discharge Permit (SDP). These four development phases (referred to as Sequencing by the City of Fort Collins) have been distinguished to aid in the appropriate timing of Big Deal Four Plex Erosion Control Report 8 installation/implementation of BMPs at different stages of the construction process. These phases are described as follows: Phase I – Grading Stage; BMPs for initial installation of perimeter controls Phase II – Infrastructure Stage; BMPs for utility, paving and curb installation Phase III – Vertical Construction Stage; BMPs for individual building construction. Phase IV – Permanent BMPs and final site stabilization. The following is a rough estimate of the anticipated construction sequence for site improvements. The schedule outlined below is subject to change as the project progresses and as determined by the contractor. Table 1 - Construction Schedule TASK BEGINNING DATE ENDING DATE BMP - PHASE OF DEVELOPMENT Building Permit TBD TBD I Removal of Existing Improvements TBD TBD I Utility Installation TBD TBD II Building Construction TBD TBD III Final Stabilization TBD TBD IV 3.5 Material Handling and Spill Prevention Potential pollution sources, as discussed in earlier sections, are to be to be identified by the contractor. Spill prevention procedures are to be determined and put in place prior to construction by the contractor. A spill and flooding response procedure must also be determined and put in place prior to construction by the contractor. Additionally, steps should be taken to reduce the potential for leaks and spills to come in contact with stormwater runoff, such as storing and handling toxic materials in covered areas or by storing chemicals within berms or other secondary containment devices. A notification procedure must be put in place by the contractor, by which workers would first notify the site construction superintendent. Depending on the severity of the spill, the site construction superintendent would possibly notify the Colorado Department of Public Health and Environment - Water Quality Control Division, downstream water users or other appropriate agencies. The release of any chemical, oil, petroleum product, sewage, etc., which enter waters of the State of Colorado (which include surface water, ground water and dry gullies or storm sewers leading to surface water) must be reported immediately to the Division’s emergency spill reporting line at (877) 518-5608. All spills that will require cleanup, even if the spill is minor and does not need to be reported to the state, should still be reported to the City of Fort Collins Utilities office at 970-221- 6700. 3.6 Waste Management and Disposal Any waste material that currently exists on the site or that is generated by construction will be disposed of in such a manner as to not cause pollutants in stormwater discharges. If waste is to be stored on-site, it shall be in an area located a minimum of 100 feet from all drainage courses. Whenever waste is not stored in a non-porous container, it shall be in an area enclosed by a 12- Big Deal Four Plex Erosion Control Report 9 inch high compacted earthen ridge or some other approved secondary containment device. The area shall be covered with a non-porous lining to prevent soil contamination. Whenever precipitation is predicted, the waste shall be covered with a non-porous cover, anchored on all sides to prevent its removal by wind and to prevent precipitation from leaching out potential pollutants from the waste. On-site waste disposal practices, such as dumpsters, should be covered or otherwise contained as to prevent dispersion of waste materials from wind. It shall also be the responsibility of the Contractor to maintain a clean jobsite to prevent dispersion of waste material and potential pollutants into adjacent properties or waterways. Big Deal Four Plex Erosion Control Report 10 4.0 Final Stabilization and Long-Term Stormwater Management 4.1 Final Stabilization The pre-disturbance individual plant density is approximately 75 percent. The existing vegetative cover is consistent with the age and upkeep of single-family student housing. Final stabilization with an individual plant density of at least 70 percent of pre-disturbance levels, or equivalent permanent, physical erosion reduction methods will be achieved. The total disturbed area will be permanently stabilized with asphalt, concrete, concrete pavers, roof area and landscaping such as sod and planting beds. It is highly recommended that pre-construction photos be taken to clearly document vegetative conditions prior any disturbance activities. 4.2 Long-Term Stormwater Management The primary method of long-term stormwater management will remain unchanged following completion of the proposed improvements. Any waste material that currently exists on the site or that is generated by construction will be disposed of in such a manner as to not cause pollutants in stormwater discharges. If waste is to be stored on-site, it shall be in an area located a minimum of 100 feet from all drainage courses. Whenever waste is not stored in a non-porous container, it shall be in an area enclosed by a 12- inch high compacted earthen ridge or some other approved secondary containment device. The area shall be covered with a non-porous lining to prevent soil contamination. Whenever precipitation is predicted, the waste shall be covered with a non-porous cover, anchored on all sides to prevent its removal by wind and to prevent precipitation from leaching out potential pollutants from the waste. On-site waste disposal practices, such as dumpsters, should be covered or otherwise contained as to prevent dispersion of waste materials from wind. It shall also be the responsibility of the Contractor to maintain a clean jobsite to prevent dispersion of waste material and potential pollutants into adjacent properties or waterways. Big Deal Four Plex Erosion Control Report 11 5.0 Inspection and Maintenance 4.3 BMP Inspection All temporary erosion control facilities shall be inspected at a minimum of once every two (2) weeks and after each significant storm event or snowmelt. Repairs or reconstruction of BMPs, as necessary, shall occur as soon as possible in order to ensure the continued performance of their intended function. The construction site perimeter, disturbed areas, all applicable/installed erosion and sediment control measures, and areas used for material storage that are exposed to precipitation shall be inspected for evidence of, or the potential for, pollutants entering the drainage system. Erosion and sediment control measures identified herein shall be observed to ensure that they are operating correctly. Particular attention should be paid to areas that have a significant potential for stormwater pollution, such as demolition areas and vehicle entries to the site. 4.4 BMP Maintenance Any BMPs not operating in accordance with this Erosion Control Report must be addressed as soon as possible to prevent the discharge of pollutants. Preventative maintenance of all temporary and permanent erosion control BMPs shall be provided in order to ensure the continued performance of their intended function. Temporary erosion control measures are to be removed after the site has been sufficiently stabilized as determined by the City of Fort Collins. Maintenance activities and actions to correct problems shall be noted and recorded during inspections. Big Deal Four Plex Erosion Control Report 12 References 1. Geotechnical Subsurface Exploration Proposed Multi-Family 4-plex Residence 621 South Meldrum Street Fort Collins, Colorado, November 28, 2012,Soil Logic, Inc. (Soilogic Project # 12-1094). 2. Urban Storm Drainage Criteria Manual, Volumes 1-3, Urban Drainage and Flood Control District, Water Resources Publications, LLC., Denver, Colorado, Updated November 2010. APPENDIX A EROSION CONTROL PLAN | STATIC AND DYNAMIC SITE PLANS Big Deal Four Plex Project Number: 876-001 Location: Fort Collins, CO Date: February 20, 2013 Total Acres: 0.22 EROSION CONTROL MEASURE Units Estimated Quantity Unit Price Total Price L.F. 410 $1.85 $758.50 each 2 $20.00 $40.00 each 2 $75.00 $150.00 Aea Inlet Protection | Mirafi Dandy Sack each 1 $75.00 $75.00 Curb Inlet Protection (w/o grate) each 0 $75.00 $0.00 Curb Inlet Protection (w/grate) each 0 $100.00 $0.00 Rock Sock each 2 $25.00 $50.00 Vehicle Tracking Control Pad each 1 $700.00 $700.00 L.F. 325 $1.00 $325.00 per hour 0 $70.00 $0.00 acre 0.22 $1,325.00 $291.50 Sub-Total: $2,390.00 1.5 x Sub-Total: $3,585.00 Amount of security: $3,585.00 Total Acres x $1325/acre: $291.50 Sub-Total: $291.50 1.5 x Sub-Total: $437.25 Cost to Re-seed: $330.00 Minimum escrow amount: $3,000.00 Erosion Control Escrow: $3,585.00 NOTE: 'Total Acres' represents total disturbed area. Area Inlet Protection Option 3 | Miniumum Escrow Amount Final Escrow Amount Big Deal Four Plex Erosion Control Cost Estimate Vegetate Landscaped Areas Option 1 | BMP Costs Silt Fence Sawcutting Pollution Prevention Street Sweeping and Cleaning Option 2 | Cost to Re-seed Disturbed acreage Straw Wattles (9" x 10' dimension) 2/20/2013 1:55 PM D:\Projects\876-001\Drainage\Erosion\876-001_Erosion-Escrow-Estimate APPENDIX B EROSION CONTROL DETAILS INSTALLATION GUIDELINES Remove grate from frame and slip into Dandy Bag®. Tuck the enclosure flap inside to completely enclose the grate. Holding the lifting devices (do not rely on lifting devices to support the entire weight of the grate), place the grate into its frame. DANDY SACK™ The Dandy Sack™ is an open-top bag that is designed to hang underneath a storm grate to filter sediment-laden stormwater. The Difference Dandy Sack™ Makes: • Easy installation. No rebar required. • Internal straps cradle grate for added security when installing & removing. • 2ft. containment area is very manageable. • Available in 3 standard sizes. • Available with optional oil absorbents. • Available with patented curb blocking technology, Dandy Curb Sack.™ INSTALLATION GUIDELINES Remove the grate from catch basin and stand on end. Move the top lifting straps out of the way and place the grate into the Dandy Sack™ so that Dandy Drop Inlet Protection Flat Grate and Mountable Curb Inlet Protection OUR COMPANY TenCate develops and produces materials that function to increase performance, reduce costs and deliver measurable results by working with our customers to provide advanced solutions. Dandy Products exclusively by TenCate Geosynthetics have an engineered design in which suspended solids are allowed to settle out of the slowed flow and are captured prior to entering the inlet. OUR PRODUCTS DANDY BAG® The patented Dandy Bag® is designed for use with flat grates (including round) and mountable curbs to filter sediment-laden storm water. The Difference Dandy Bag® Makes: • Unique patented design keeps silt, sediment and debris out of storm systems. • Reduces the need to flush/clean inlets. • Fabricated from orange geotextile. • Easy to install, inspect, and re-use. • Reduces outflow turbidity. the grate is below the top straps and above the lower straps. Holding the lifting straps, insert the grate into the inlet. DANDY POP™ The Dandy Pop™ is designed for use with flat field grates to filter sediment-laden water. The Dandy Pop™ fully encloses the grate, virtually eliminating sediment infiltration. The Difference Dandy Pop™ Makes: • Unique patented design keeps silt, sediment and debris out of storm systems. • Easily visible to machine operators in the field. Property Test Method Units Marv Grab Tensile Strength (MD x CD) Grab Tensile Elongation Puncture Strength Mullen Burst Strength Trapezoid Tear Strength (MD x CD) Percent Open Area (POA) Apparent Opening Size (AOS) Permittivity Permeability Water Flow Rate Ultraviolet Resistance Color ASTM D 4632 ASTM D 4632 ASTM D 4833 ASTM D 3786 ASTM D 4533 COE -22125-86 ASTM D 4751 ASTM D 4491 ASTM D 4491 ASTM D 4491 ASTM D 4355 1.62 (365) x 0.89 (200) 24 x 10 0.40 (90) 3097 (450) 0.51 (115) x 0.33 (75) 10 0.425 (40) 2.1 0.14 5907 (145) 90 Orange1 kN (lbs) % kN (lbs) kPa (psi) kN (lbs) % mm (US Std Sieve) sec-1 cm/sec l/min/m2 (gal/min/ft2) % Technical Data for FW® 402 Geotextile 1The orange color geotextile is a trademark of Dandy Products, Inc. US Patent No. 5,725,782, 6,010,622, & 6,749,366 Dandy Drop Inlet Protection Flat Grate and Mountable Curb Inlet Protection 365 South Holland Drive Pendergrass, GA 30567 Tel 800 685 9990 Tel 706 693 2226 Fax 706 693 4400 www.mirafi.com PDS.DROP0508 TenCateTM Geosynthetics North America does not assume liability for the accuracy or completeness of this information or for the ultimate use by the purchaser. TenCateTM Geosynthetics North America disclaims Street Sweeping and Cleaning S-11 November 2010 Urban Drainage and Flood Control District SWC-1 Urban Storm Drainage Criteria Manual Volume 3 Photograph SSC-1. Monthly street sweeping from April through November removed nearly 40,690 cubic yards of sediment/debris from Denver streets in 2009. Photo courtesy of Denver Public Works. Description Street sweeping uses mechanical pavement cleaning practices to reduce sediment, litter and other debris washed into storm sewers by runoff. This can reduce pollutant loading to receiving waters and in some cases reduce clogging of storm sewers and prolong the life of infiltration oriented BMPs and reduce clogging of outlet structures in detention BMPs. Different designs are available with typical sweepers categorized as a broom and conveyor belt sweeper, wet or dry vacuum-assisted sweepers, and regenerative-air sweepers. The effectiveness of street sweeping is dependent upon particle loadings in the area being swept, street texture, moisture conditions, parked car management, equipment operating conditions and frequency of cleaning (Pitt et al. 2004). Appropriate Uses Street sweeping is an appropriate technique in urban areas where sediment and litter accumulation on streets is of concern for aesthetic, sanitary, water quality, and air quality reasons. From a pollutant loading perspective, street cleaning equipment can be most effective in areas where the surface to be cleaned is the major source of contaminants. These areas include freeways, large commercial parking lots, and paved storage areas (Pitt et al. 2004). Where significant sediment accumulation occurs on pervious surfaces tributary to infiltration BMPs, street sweeping may help to reduce clogging of infiltration media. In areas where construction activity is occurring, street sweeping should occur as part of construction site stormwater management plans. Vacuuming of permeable pavement systems is also considered a basic routine maintenance practice to maintain the BMP in effective operating condition. See the maintenance chapter for more information on permeable pavement systems. Not all sweepers are appropriate for this application. Practice Guidelines1 1. Post street sweeping schedules with signs and on local government websites so that cars are not parked on the street during designated sweeping days. 2. Sweeping frequency is dependent on local government budget, staffing, and equipment availability, but monthly sweeping during non-winter months is a common approach in the metro Denver urban 1 Practice guidelines adapted from CASQA (2003) California Stormwater BMP Handbook, Practice SC-70 Road and Street Maintenance. S-11 Street Sweeping and Cleaning SWC-2 Urban Drainage and Flood Control District November 2010 Urban Storm Drainage Criteria Manual Volume 3 Changes in Street Sweeper Technology (Source: Center for Watershed Protection 2002) At one time, street sweepers were thought to have great potential to remove stormwater pollutants from urban street surfaces and were widely touted as a stormwater treatment practice in many communities. Street sweeping gradually fell out of favor, largely as a result of performance monitoring conducted as part of the National Urban Runoff Program (NURP). These studies generally concluded that street sweepers were not very effective in reducing pollutant loads (USEPA, 1983). The primary reason for the mediocre performance was that mechanical sweepers of that era were unable to pick up fine-grained sediment particles that carry a substantial portion of the stormwater pollutant load. In addition, the performance of sweepers is constrained by that portion of a street’s stormwater pollutant load delivered from outside street pavements (e.g., pollutants that wash onto the street from adjacent areas or are directly deposited on the street by rainfall). Street sweeping technology, however, has evolved considerably since the days of the NURP testing. Today, communities have a choice in three basic sweeping technologies to clean their urban streets: traditional mechanical sweepers that utilize a broom and conveyor belt, vacuum-assisted sweepers, and regenerative-air sweepers (those that blast air onto the pavement to loosen sediment particles and vacuum them into a hopper). For more information, see http://www.cwp.org/Resource_Library/Center_Docs/PWP/ELC_PWP121.pdf area. Consider increasing sweeping frequency based on factors such as traffic volume, land use, field observations of sediment and trash accumulation, proximity to watercourses, etc. For example:  Increase the sweeping frequency for streets with high pollutant loadings, especially in high traffic and industrial areas.  Conduct street sweeping prior to wetter seasons to remove accumulated sediments.  Increase the sweeping frequency for streets in special problem areas such as special events, high litter or erosion zones. 3. Perform street cleaning during dry weather if possible. 4. Avoid wet cleaning the street; instead, utilize dry methods where possible. 5. Maintain cleaning equipment in good working condition and purchase replacement equipment as needed. Old sweepers should be replaced with more technologically advanced sweepers (preferably regenerative air sweepers) that maximize pollutant removal. 6. Operate sweepers at manufacturer recommended optimal speed levels to increase effectiveness. 7. Regularly inspect vehicles and equipment for leaks and repair promptly. 8. Keep accurate logs of the number of curb-miles swept and the amount of waste collected. 9. Dispose of street sweeping debris and dirt at a landfill. 10. Do not store swept material along the side of the street or near a storm drain inlet. Clearing & Grading Development Standards Page 123 Source: http://www.ci.bellevue.wa.us/pdf/Development%20Services/CG_DevStds2010_BMPC152.pdf BMP C152: Sawcutting and Surfacing Pollution Prevention SPP Purpose Sawcutting and surfacing operations generate slurry and process water that contains fine particles and high pH (concrete cutting), both of which can violate the water quality standards in the receiving water. This BMP is intended to minimize and eliminate process water and slurry from entering waters of the State. Conditions of Use Anytime sawcutting or surfacing operations take place, these management practices shall be utilized. Sawcutting and surfacing operations include, but are not limited to, the following: Sawing Coring Grinding Roughening Hydro-demolition Bridge and road surfacing Design and Installation Specifications Slurry and cuttings shall be vacuumed during cutting and surfacing operations. Slurry and cuttings shall not remain on permanent concrete or asphalt pavement overnight. Slurry and cuttings shall not drain to any natural or constructed drainage conveyance. Collected slurry and cuttings shall be disposed of in a manner that does not violate groundwater or surface water quality standards. Process water that is generated during hydro-demolition, surface roughening or similar operations shall not drain to any natural or constructed drainage conveyance and shall be disposed of in a manner that does not violate groundwater or surface water quality standards. Cleaning waste material and demolition debris shall be handled and disposed of in a manner that does not cause contamination of water. If the area is swept with a pick-up sweeper, the material must be hauled out of the area to an appropriate disposal site. Maintenance Standards Continually monitor operations to determine whether slurry, cuttings, or process water could enter waters of the state. If inspections show that a violation of water quality standards could occur, stop operations and immediately implement preventive measures such as berms, barriers, secondary containment, and vacuum trucks. APPENDIX C LANDSCAPE PLAN any and all express, implied, statutory standards, warranties, guarantees, including without limitation any implied warranty as to merchantability or fitness for a particular purpose or arising from a course of dealing or usage of trade as to any equipment, materials, or information furnished herewith. This document should not be construed as engineering advice. Mirafi® is a registered trademark of TenCateTM Geosynthetics North America. ISO 9001 FM 61026 • Pops open in a second. • Dome design provides easy cleaning and maintenance. • Standard sizes to fit any grate. INSTALLATION GUIDELINES Pop open the Dandy Pop™ near the inlet. Remove grate from frame and place into Dandy Pop™. Pull up slack and seal hook and loop fastener to enclose the grate. Holding the lifting straps, insert the grate into the inlet making sure that the grate seats completely in the frame. Dandy Bag® Dandy Sack™ Dandy Pop™ Protective & Outdoor Fabrics Aerospace Composites Armour Composites Geosynthetics Industrial Fabrics Synthetic Grass TM