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Home My WebLink AboutWPO201800004 Plan - E&S 2018-02-06 EROSION AND SEDIMENT CONTROL NARRATIVE FOR FREE BRIDGE OFFICE January 31, 2018 LOCATION: Tax Map 78, Parcels 11A1 and 57B Rivanna District, Albemarle County, Virginia OWNERS: ��p`��Qcp �� a Tax Map 78 Parcel 11 Pp�beocc\e� F&S Financial Marketing, Inc `0\ \C eye / � Charlottesville, Virginia 22911 �v�� • A Tax Map 78 Parcel 57B Free Bridge Auto Sales 1400 Richmond Road Charlottesville, Virginia 22911 Ae DEVELOPER: ��j, T Free Bridge Auto Sales 1400 Richmond Road Charlottesville, Virginia 22911 IQ MICH 4- F. MYERS • I. No.33028 PREPARED BY: Dominion Engineering & Design %%NAL 'G3 172 South Pantops Road Charlottesville, VA 22911 434.979.8121 A. MINIMUM STANDARDS (MS): All applicable Virginia Erosion and Sediment Control Regulations and Minimum Standards shall be adhered to during all phases of construction. These include, but are not limited to the following: 1. STABLIZATION OF DENUDED AREAS: Permanent or temporary soil stabilization shall be applied to bare areas within seven days after final grade is reached on any portion of the site. Temporary soil stabilization shall be applied within seven days to denuded areas that may not be at final grade, but will remain dormant or undisturbed for longer than 30 days. Permanent stabilization shall be applied at areas that are to be left dormant for more than 1 year. 2. STABILIZATION OF SOIL STOCKPILES: During construction of the project, soil stockpiles shall be stabilized or protected with sediment trapping measures. The applicant is responsible for temporary protection and permanent stabilization of all soil stockpiles on site as well as soil intentionally transported from the project site. 3. PERMANENT VEGETATIVE COVER A permanent vegetative cover shall be established on denuded areas not otherwise permanently stabilized. Permanent vegetation shall not be considered established until a ground cover is achieve that, in the opinion of the county Inspector, is uniform and mature enough to survive to inhibit erosion. 4. TIMING & STABILIZATION OF SILT TRAPPING MEASURES: Sediment basins and traps, perimeter dikes, sediment barriers and other measures intended to trap sediment shall be constructed as a first step in any land disturbing activity and shall be made functional before upslope land disturbance takes place. 5. STABILIZATION OF EARTHEN STRUCTURES: Stabilization measures shall be applied to earthen structures such as dams, dikes and diversions immediately after installation. 6. SEDIMENT TRAPS AND BASINS: A sediment basin shall control surface runoff from disturbed areas that is comprised of flow from drainage areas greater than or equal to three acres. The sediment basin shall be designed and constructed to accommodate the anticipated sediment loading for the land disturbing activity. The outfall device or system device shall take into account the total drainage area flowing through the disturbed area to be served by the basin. 7. CUT AND FILL SLOPES: Cut and fill slopes shall be designed and constructed in a manner that will minimize erosion. Slopes that are found to be eroding excessively within one year of permanent stabilization shall be provided with additional slope stabilizing measures until the problem is corrected. 8. CONCENTRATED RUN-OFF DOWN CUT OR FILL SLOPES: Concentrated runoff shall not flow down cut or fill slopes unless contained within an adequate temporary or permanent channel, flume, or slope drain structure. 9. WATER SEEPS FROM A SLOPE FACE: Whenever water seeps from a slope face, adequate drainage or other protection shall be provided. 1 10. STORM SEWER INLET PROTECTION: All storm sewer inlets that are made operable during construction shall be protected so that sediment-laden water cannot enter the conveyance system without first being filtered or otherwise treated to remove sediment. 11. STABILIZATION OF OUTLETS: Before newly constructed stormwater conveyance channels are made operational, adequate outlet protection and any required temporary or permanent channel lining shall be installed in both the conveyance channel and receiving channel. 12. WORK IN LIVE WATERCOURSES: When work in a live watercourse is performed, precautions shall be taken to minimize encroachment, control sediment transport and stabilize the work area to the greatest extent possible during construction. Nonerodible material shall be used for the construction of causeways and cofferdams. Earthen fill may be used for these structures if armored by nonerodible cover materials. 13. CROSSING A LIVE WATERCOURSE: When a live watercourse must be crossed by construction vehicles more than twice in any six month period, a temporary stream crossing constructed of nonerodible materials shall be provided. 14. APPLICABLE REGULATIONS: All applicable federal, state and local regulations pertaining to working in or crossing live watercourses shall be met. 15. STABILIZATION OF BED AND BANKS The bed and banks of a watercourse shall be stabilized immediately after work in the watercourse is completed. 16. UNDERGROUND UTILITIES: Underground utilities shall be installed in accordance with the following standards in addition to other criteria: a. No more than 500 linear feet of trench may be opened at one time. b. Excavated material shall be placed on the uphill side of trenches c. Effluent for dewatering operations shall be filtered or passed through approved sediment trapping device, or both, and discharged in a manner that does not adversely affect flowing streams or offsite property. d. Material used for backfilling trenches shall be properly compacted in order to minimize erosion and promote stabilization. e. Restabilization shall be accomplished in accordance with these regulations. f. Applicable safety regulations shall be complied with. 17. CONSTRUCTION ACCESS ROUTES: Where construction vehicle access routes intersect paved public roads, provisions shall be made to minimize the transport of sediment by vehicular tracking onto paved surfaces. Where sediment is transported on to a public road surface, the road shall be cleaned thoroughly at the end of each day. Sediment shall be removed by shoveling or sweeping and transported to a sediment control disposal area. Street washing shall be allowed only after sediment is removed in this manner. This provision shall apply to individual lots as well as to larger land disturbing activities. 2 18. TEMPORARY E&S CONTROL MEASURE REMOVAL: All temporary erosion and sediment control measures shall be removed within 30 days after final site stabilization or after temporary measures are no longer needed, unless otherwise authorized by the local program authority. Trapped sediment and the disturbed soil areas resulting from the disposition of temporary measures shall be permanently stabilized to prevent further erosion and sediment. 19. ADEQUACY OF RECEIVING CHANNELS: Properties and waterways downstream from the development site shall be protected from sediment deposition, erosion and damage, due to increases in volume, velocity and peak flow rates of stormwater runoff for the stated frequency storm of 24-hour duration. B1. PROJECT DESCRIPTION: The purpose of this project is to construct a 6,000 SF, two-story building and the parking required for the use. The total area to be disturbed 1.16 acres. B2. EXISTING SITE CONDITIONS: The site is graded such that site runoff flows via overland flow to a ditch running along the northern edge of the property from flowing from east to west to an existing drop inlet located at the northwestern edge of the property. B3. ADJACENT AREAS: The site is bounded to the West by Kia Auto. To the North by Olympia Drive. To the South by Free Bridge Auto and to the East by the proposed Monscane Center Site Plan. B4. SOIL DESCRIPTIONS: According to the Albemarle County Soils Survey conducted by the United States Department of Agriculture Soil Conservation Service, the primary soil types that may be disturbed during this scope of work have been identified as the following: 1. Rabun clay loam (71C) — Permeability is moderate, surface runoff is rapid, and the hazard of erosion is severe. Hydrologic group B, K factor .32 2. Catoctin silt loam (12E) Permeability is moderately rapid, surface runoff is very rapid, and the hazard of erosion is very severe. Hydrologic group C, K factor .32 B5. CRITICAL AREAS: There are critical slopes located on this site. Refer to Sheet C3 of the plans for location. B6. EROSION AND SEDIMENT CONTROL MEASURES: Unless otherwise indicated, all erosion and sediment control practices will be constructed and maintained according to the minimum standards and specifications as set forth in the Virginia Erosion and Sediment Control Handbook, latest edition. The minimum standards of the Virginia Erosion and Sediment Control Regulations shall be adhered to unless otherwise waived or approved by variance. TEMPORARY CONSTRUCTION ENTRANCE (CE) — 3.02 An asphalt pad shall be constructed at the entrance of the project site to provide a means of removing sediment from the tires of construction vehicles leaving the work site via a wash rack. The Contractor shall remove any mud from the existing road surface by means of sweeping and shoveling, in the event the asphalt pad is not adequate in sediment removal. 3 SILT FENCE (SF) — 3.05 Silt fencing will be installed as a first step in construction activities. Location and details are shown on the plans. STORM DRAIN INLET PROTECTION (IP) — 3.07 A sediment filter around a storm drain drop inlet or curb inlet used to prevent sediment from entering storm drainage systems prior to permanent stabilization of the disturbed area. Location and details of inlet protection are shown on the plans. TEMPORARY DIVERSION DIKE (DD) — 3.09 A temporary diversion dike will be installed before site grading begins, for the purposes of diverting storm and sediment-laden runoff to the appropriate outlet or trapping facility. Location and details are shown on the plans. DUST CONTROL (DC) —3.39 A variety of methods are available to prevent surface and air movement of dust from exposed soil surfaces and reduce the presence of airborne substances which may present health hazards, traffic safety problems or harm animal or plant life. B7. PERMANENT AND TEMPORARY STABILIZATION: TOPSOILING — 3.30 Topsoil may be stripped from the area to be graded and stockpiles for later use. All stockpiles which will be left dormant for more than 30 days shall be temporarily seeded. A topsoil stockpile may be selected onsite by the developer and shall be temporarily protected with surrounding silt fencing. TEMPORARY SEEDING — 3.31 Temporary soil stabilization shall be applied within 7 days to denuded areas that may not be at final grade, but will remain dormant (undisturbed) for longer than 30 days and less than 1 year. This includes, but is not limited to areas such as soil stockpiles. Seeded areas shall be limed when necessary at a rate of 2 tons per acre, and fertilized at a rate of 450 lbs. per acre of 10-20-20 (10 lbs. per 1,000 square feet) or equivalent. A Temporary Seeding Schedule is attached for proper seed selection. PERMANENT SEEDING — 3.32 A perennial vegetative covering shall be established on disturbed areas within 7 days of being brought to final grade on areas not otherwise protected. Selection of the seed mixture shall depend on the time of year it is to be applied according to the Permanent Seed Schedule as shown on the drawing. Seeded areas shall be limed when necessary at a rate of 2 tons per acres, and fertilized at a rate of 1,000 lbs. per acre of 10-20-10 (10 lbs. per 1,000 square feet) or equivalent. MULCHING — 3.35 All seeded areas shall be mulched with straw immediately following seeding operations. Straw mulch shall be applied at a rate of two tons per acre. 4 B8. SOIL STOCKPILES AND BORROW AREAS There will be no onsite borrow areas. Any excess fill material required for construction shall be hauled to the site from a location with an approved E&SC plan. Excess soils shall be hauled to the adjacent Pavilions at Pantops site. B9. OFF-SITE AREAS: Any required material needed for the site will be supplied by an area with an approved WPO plan number. B10. STORM WATER MANAGEMENT: Stormwater detention for this property is provided by an offsite facility located to the east of the site. The SWM basin in question was approved under a plan "Amendment to SWM Plans for Luxor & North Pantops Commercial." Runoff will leave the site via existing storm sewer pipe flow starting at the existing inlet located at the northwest corner of the site. The 36" outfall pipe runs across Olympia Drive and then turns to the east and flows directly to the aforementioned pond. The post-developed hydrologic coefficient for this project is 0.66 --- [(28,121 SFx0.9 + 22,321SFx0.35)/50,442 SF]. An adequate outfall analysis plan has been provided to indicate an adequate outfall to the pond facility within an existing storm sewer pipe system within existing storm drainage easements. B11. MAINTENANCE SCHEDULE: A program of maintenance for the erosion and sediment controls specified in this narrative and shown on the plans are recommended as follows: 1. The Site Superintendent or his representative shall make a visual inspection of all erosion and sediment controls on a daily basis until the site is stabilized and especially after a heavy rainfall to assure that all controls are in place and that none have been damaged. Any damaged control shall be repaired prior to the end of each workday to include re-seeding if necessary. 2. All silt trapping devices shall be cleaned out at 50 percent capacity and sediment shall be disposed of by spreading on site. 3. Gravel outlets shall be checked regularly for sediment buildup that may prevent drainage. Controls shall be inspected and repaired after each rainfall and cleaned if sediment has accumulated to half of the device's original height. 4. All earthen structures such as diversion dikes and berms shall be checked daily during construction for breaching by equipment. Repairs shall be made immediately. 5. Silt fences shall be checked after each rainstorm to assure they have not fallen or become clogged with silt. All repairs shall be made immediately. 6. All seeded areas shall be inspected regularly to see that good stand is maintained. Areas will be re-fertilized and re-seeded as necessary. 7. After construction operations have ended and disturbed areas have been stabilized, all berms and sediment-trapping devices may be removed after removal, the ground shall be restored to its natural or proposed condition to include establishment of permanent vegetation. Removal of any control is contingent upon approval of the County Inspector. 5 B12. CONSTRUCTION SEQUENCE See ESC Plan for construction sequence. B12. GENERAL CONSTRUCTION NOTES FOR EROSION AND SEDIMENT CONTROL PLANS: 1. The plan approving authority must be notified one week prior to the pre-construction conference, one week prior to the commencement of land disturbing activity, and one week prior to the final inspection. 2. All erosion and sediment control measures will be constructed and maintained according to minimum standards and specifications of the Virginia Erosion and Sediment Control Handbook and Virginia Regulations VR 625-02-00 Erosion and Sediment Control Regulations. 3. All erosion and sediment control measures are to be placed prior to or as the first step in clearing. 4. A copy of the approved erosion and sediment control plan shall be maintained on the site at all times. 5. Prior to commencing land disturbing activities in areas other than indicated on these plans (including, but not limited to, off-site borrow or waste areas), the contractor shall submit a supplementary erosion control plan to the owner for review and approval by the plan approving authority. 6. The contractor is responsible for installation of any additional erosion control measures necessary to prevent erosion and sedimentation as determined by the plan approving authority. 7. All disturbed areas are to drain to approved sediment control measures at all times during land disturbing activities and during site development until final stabilization is achieved. 8. During dewatering operations, water will be pumped into an approved filtering device. 9. The contractor shall inspect all erosion control measures periodically and after each runoff- producing rainfall event. Any necessary repairs or cleanup to maintain the effectiveness of the erosion control devices shall be made immediately. 10. All fill material to be taken from an approved, designated borrow area. 11. All waste materials shall be taken to an approved waste area. Earth fill shall be inert materials only, free of roots, stumps, wood, rubbish, and other debris. 12. Borrow or waste areas are to be reclaimed within 7 days of completion per Zoning Ordinance section 5.1.28. 13. All inert materials shall be transported in compliance with section 13-301 of the Code of Albemarle. 14. Borrow, fill or waste activity involving industrial-type power equipment shall be limited to the hours of 7:00am to 9:00pm. 15. Borrow, fill or waste activity shall be conducted in a safe manner than maintains lateral support, or order to minimize any hazard to persons, physical damage to adjacent land and improvements, and damage to any public street because o slides, sinking, or collapse. 16. The developer shall reserve the right to install, maintain, remove or convert to permanent stormwater management facilities where applicable all erosion control measures required by this plan regardless of the sale of any lot, unit, building or other portion of the property. 17. Temporary stabilization shall be temporary seeding and mulching. Seeding is to be at 75 lbs/acre, and in the months of September to February to consist a 50/50 mix of Annual Ryegrass and Cereal Winter Rye, or in March and April to consist of Annual Rye, or May through August to consist of German Millet. Straw mulch is to be applied at 80Ibs/100sf. Alternatives are subject to approved by the County erosion control inspector. • 6 18. Permanent stabilization shall be lime and fertilizer, permanent seeding, and mulch. Agricultural grade limestone shall be applied at 90lbs/1000sf, incorporated into the top 4-6 inches of soil. Fertilizer shall be applied at 1000Ibs/acre and consist of a 10-20-10 nutrient mix. Permanent seeding shall be applied at 1801bs/acre and consist of 95% Kentucky 31 or Tall Fescue and 0-5% Perennial Ryegrass or Kentucky Bluegrass. Straw mulch is to be applied at 80Ibs/100sf. Alternatives are subject to approved by the County erosion control inspector. 19. Maintenance: All measures are to be inspected weekly and after each rainfall. Any damage or clogging to structural measures is to be repair immediately. Silt traps are to be cleaned when 50% of the wet storage volume is filled with sediment. All seeded areas are to be reseeded when necessary to achieve a good stand of grass. Silt fence and diversion dykes which are collecting sediment to half their height must be cleaned and repaired immediately. 20. All temporary erosion and sediment control measures are to be removed within 30 days of final site stabilization, when measures are no longer needed, subject to approval by the County erosion control inspector. ,.t4,1 !•L i. 7 Y I I�UMu v1O�' T1013M9OJ3V3CI