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HomeMy WebLinkAboutWPO201300036 Assessment - Environmental 2013-05-20 KEENEY & CO., ARCHITECTS, PLC Ronald M. Keeney, RA, NCARB, CS!, CDT 1413 Sachem Place, Suite One Charlottesville, VA 22901-2497 (434) 978-2000 Fax:978-7438 FIRST BAPTIST CHURCH OF COVESVILLE ALBEMARLE COUNTY JUNE 17,2010 EROSION AND SEDIMENT CONTROL NARRATIVE Project Description: The proposed work includes grading the areas to be developed with an additional church building. The total area of the lot is 3.03 acres, of which 1.6 acres maximum will be involved in the construction. There will not be any off-site land disturbed for this project. Existing Site Conditions:The land presently has a brick one story with basement sanctuary building and a small framed storage shed,both to remain.There is a cemetery along the edge of the tree line at the western part of the site.The land generally slopes toward the south.The area proposed for construction is currently cleared and graded. Adjacent Property: The site is located on State Route 805, an unimproved driveway not subject to state maintenance. The site is bound by State Route 805,Up&Over Farm LLC., and single family residences. Urban Land: The existing site is graded and has an established grass lawn. Only minor grading around the proposed construction area is anticipated, and will be re-established as lawn. Critical Erosion Areas: There is a existing manmade critical slope adjacent to an exterior flight of stairs. A critical slopes waiver has been requested for this area. Erosion and Sediment Control Measures: Unless otherwise indicated, all vegetative and structural erosion and sediment control practices will be constructed and maintained according to minimum standards and specifications of the Virginia Erosion and Sediment Control Handbook. Additional measures may be required during construction by the County Erosion Control Official, as needed. STRUCTURAL PRACTICES: Construction Entrance: (CE) 3.02 A paved pad shall be located at points of vehicular ingress and egress on a construction site. Silt Fence:(SF) 3.05 Silt fence shall be constructed along the lower limit of the graded area. Diversion Dike: (DD) 3.09 A ridge of compacted soil constructed to divert sediment-laden runoff to a sediment trapping structure. Permanent Seeding:(PS) 3.32 Establishment of perennial vegetative cover by planting seed on rough-graded areas that will not be brought to final grade for a year or more or where permanent, long-lived vegetative cover is needed on fine-graded areas. Temporary Sediment Trap: (ST) 3.13 A small ponding area, formed by constructing an earthen embankment with a stone outlet across a drainage swale, to detain sediment-laden runoff from small disturbed areas for enough time to allow most of the suspended solids to settle out. Maximum effective life is 18 months. VEGETATIVE PRACTICES: Permanent Stabilization 3.32: All areas disturbed by construction will be stabilized by establishing a good stand of grass or other landscaping in all areas not covered by building or pavement. All disturbed areas shall be fertilized, seeded, and mulched within 7 days after the completion of grading, according to the following: Lime 3.32: Amount to be determined by Soil Test, or 3 tons per acre of pulverized agricultural limestone, uniformly applied to surface to be seeded during seedbed preparation and incorporated into the top 4-6 inches of soil. Fertilizer 3.32: 1000 pounds per acre of 5-20-10 or equivalent,uniformly applied to the surface to be seeded during seedbed preparation and incorporated into the top 4-6 inches of soil. Seed 3.32: One hundred eight (108) pounds per acre of Tall Fescue variety KY-31, 2 pounds per acre of Red Top Grass,20 pounds per acre of Seasonal Nurse Crop, and 20 pounds per acre of Crownvetch. Seasonal Nurse Crop shall be as follows: Feb. 16 through April use Annual Rye; May 1 through Aug. 15 use Foxtail Millet; Aug. 16 through October use Annual Rye; November through February 15 use Winter Rye. Seed shall be of the latest seed crop available and shall have been tested within six months of the date of seeding and meet the requirements of the Virginia Field Seed Law. Mulch 3.35: Straw or hay mulch shall be spread at the rate of 1.5 to 2 tons per acre (minimum 2 tons per acre for winter cover). Mulch shall be free from weeds and course matter,must be anchored,and may be hand or machine spread. Mulch shall be applied as soon as possible after seeding. In no case shall mulching be delayed more than 48 hours. MANAGEMENT STRATEGIES: Construction should be sequenced so that grading operations can begin and end as quickly as possible. Areas that are not to be disturbed shall be clearly marked by the placement of the erosion control measures prior to construction. The job superintendent shall be responsible for the installation and maintenance of all erosion and sediment measures. The work should be completed within about 3 months. Where construction vehicle access routes intersect paved public roads, provisions shall be made to minimize the transport of sediment by vehicular tracking onto the paved surface. Where sediment is transported onto a public road surface, the road shall be cleaned thoroughly at the end of each day. Sediment shall be removed from the roads 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 subdivision lots as well as to larger land-disturbing activities. Stabilization of Denuded Areas and Soil Stockpiles: Permanent or temporary soil stabilization must be applied to denuded areas within 7 days after final grade is reached on any portion of the site. Temporary soil stabilization shall be applied within 7 days to denuded areas which may not be at final grade but will remain dormant (undisturbed) for longer than 30 days. Permanent stabilization shall be applied to areas that are to be left dormant for more than one year. (Soil stabilization refers to measures that protect soil from the erosive forces of raindrop impact and flowing water. Applicable practices include vegetative establishment, mulching and the early application of gravel base on areas to be paved. Soil stabilization measures should be selected to be appropriate for the time of year, site conditions and estimated duration of use.) Timing and Stabilization of Sediment Trapping Measures: Sediment barriers 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. Stabilization measures shall be applied to earthen structures such as dams, dikes,and diversions immediately after installation. Disposal of Temporary Measures: All temporary erosion and sediment control measures shall be removed within 30 days after final site stabilization or after the temporary measures are no longer needed, unless otherwise authorized by the local program administrator. Trapped sediment and the disturbed soil areas resulting from the disposition of temporary measures shall be permanently stabilized to prevent further erosion and sedimentation. Maintenance:All erosion and sediment control structures and systems shall be maintained, inspected, and repaired weekly and after each significant rainfall and as needed to insure continued performance of their intended function. Any damage to structural measures shall be repaired immediately. Silt traps are to be cleared at 50% storage capacity level. All seeded areas are to be checked to insure a good stand is maintained. Stormwater Management: Stormwater management is provided by a single bio-filter and a level spreader on site which services onsite and some offsite stormwater. GENERAL EROSION AND SEDIMENT CONTROL NOTES: ES-1: Unless otherwise indicated,all vegetative and structural erosion and sediment control practices 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. ES-2: 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. ES-3: All erosion and sediment control measures are to be placed prior to or as the first step in clearing. ES-4: A copy of the approved erosion and sediment control plan shall be maintained on the site at all times. ES-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/ owner shall submit a supplementary erosion control plan for review and approval by the plan- approving authority. ES-6: The contractor/owner is responsible for installation of any additional erosion control measures necessary to prevent erosion and sedimentation as determined by the plan approving authority. ES-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. ES-8: During dewatering operations, water will be pumped into an approved filtering device. ES-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. MINIMUM STANDARDS MS-1 Permanent or temporary soil stabilization must be applied to denuded 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 (undisturbed) for longer than 30 days. Permanent stabilization shall be applied to areas that are to be left dormant for more than one year. Soil stabilization refers to measures which protect soil from the erosive forces of raindrop impact and flowing water. Applicable practices include vegetative establishment, mulching,and the early application of gravel base on areas to be paved. Soil stabilization measures should be selected to be appropriate for the time of year, site conditions and estimated duration of use. MS-2 During construction of the project, soil stockpiles and borrow areas shall be stabilized or protected with sediment trapping measures. The applicant is responsible for the temporary protection and permanent stabilization of all soil stockpiles on site as well as borrow areas and soil intentionally transported from the project site. MS-3 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 achieved that, is uniform,mature enough to survive and will inhibit erosion. MS-4 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. MS-5 Stabilization measures shall be applied to earthen structures such as dams, dikes, traps, basins and diversions immediately after installation. MS-6 Surface runoff from disturbed areas that is comprised of flow from drainage areas greater than or equal to three acres shall be controlled by a sediment basin. The sediment basin shall be designed and constructed to accommodate the anticipated • sediment loading from the land disturbing activity. The outfall device or system design shall take into account the total drainage area flowing through the disturbed area to be served by the basin. MS-7 Cut and fill slopes shall be 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. MS-8 Concentrated runoff shall not flow down cut or fill slopes unless contained within an adequate temporary or permanent channel, flume, or slope drain structure. MS-9 Whenever water seeps from a slope face,adequate drainage or other protection shall be provided. MS-10 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. MS-11 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. MS-12 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 with nonerodible cover materials. MS-13 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 material shall be provided. MS-14 All applicable federal, state and local regulations pertaining to working in or crossing live watercourses shall be met. MS-15 The bed and banks of a watercourse shall be stabilized immediately after the work in the watercourse is completed. MS-16 Underground utility lines shall be installed in accordance with the following standards in addition to other applicable 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 from dewatering operations shall be filtered or passed through an approved sediment trapping device, or both, and discharged in a manner that does not adversely affect flowing streams or off-site property. d. Restabilization shall be accomplished in accordance with these regulations. e. Applicable safety regulations shall be complied with. • MS-17 Where construction vehicle access routes intersect paved public roads,provisions shall be made to minimize the transport of sediment by vehicular tracking onto the paved surface. Where sediment is transported onto a public road surface,the road shall be cleaned thoroughly at the end of the day. Sediment shall be removed from the roads 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. MS-18 All temporary erosion and sediment control measures shall be removed within 30 days after final site stabilization or after the temporary measures are no longer needed,unless otherwise authorized by the local program administrator. Trapped sediment and the disturbed soil areas resulting from the disposition of temporary measures shall be permanently stabilized to prevent further erosion and sedimentation.