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HomeMy WebLinkAboutWPO202100047 VSMP - SWPPP 2021-08-13Clover Dam Spillway Design Storm Water Pollution Prevention Plan (SWPPP) For Construction Activities Inventory Number #003162 Albemarle County, Virginia F&R Record No.: 84X-0009 Prepared For: West Leigh Committee of Three 2390 Kingston Road Charlottesville, Virginia 22901 434-987-5755 Prepared By: FROEHLING & ROBERTSON, INC. 1734 Seibel Drive, NE Roanoke, Virginia 24012 Phone: (540) 344-7939 Fax: (540) 344-3657 17 May 2021 Prepared by: David A Krisnitski Z No. 36465 David A. Krisnitski, P.E. Water Resources Engineer Reviewed by: TABLE OF CONTENTS 1.0 PURPOSE....................................................................................................................2 1.1 REGULATORY BACKGROUND........................................................................................... 2 1.2 STORM WATER POLLUTION PREVENTION PLAN ORGANIZATION ............................................... 2 2.0 FACILITY DESCRIPTION...............................................................................................3 2.1 GENERAL................................................................................................................... 3 2.2 DRAINAGE SYSTEM...................................................................................................... 3 2.3 SITE DESCRIPTION........................................................................................................ 3 2.4 CONSTRUCTION PROJECT SITE MAPS................................................................................ 5 3.0 NON -STORM WATER DISCHARGES..............................................................................5 3.1 APPLICABLE LAWS....................................................................................................... 5 3.2 HANDLING AND DISPOSAL OF HAZARDOUS MATERIALS......................................................... 6 3.3 NOTICE, RESPONSE, AND REMEDIATION OF HAZARDOUS MATERIALS INCIDENTS .......................... 6 3.4 NOTICE OF ENVIRONMENTAL PERMITTING......................................................................... 6 3.5 UNDERGROUND STORAGE TANKS.................................................................................... 6 3.6 ABOVE GROUND STORAGE TANKS................................................................................... 7 3.7 RIGHT TO KNOW......................................................................................................... 7 3.8 PENALTIES................................................................................................................. 7 3.9 RESPONSIBILITY OF THE OWNER...................................................................................... 7 4.0 STORM WATER MANAGEMENT CONTROLS................................................................. 7 4.1 BEST MANAGEMENT PRACTICES FOR CONSTRUCTION ACTIVITIES ............................................. 7 4.2 EROSION AND SEDIMENT CONTROL.................................................................................. 7 4.3 POST CONSTRUCTION STORM WATER MANAGEMENT........................................................... 8 5.0 MONITORING AND DOCUMENTATION........................................................................8 5.1 SITE INSPECTIONS........................................................................................................ 8 5.2 PERSONNEL DESIGNATION............................................................................................. 8 5.3 SWPPP CONTENT REVIEW............................................................................................ 8 5.4 CERTIFICATION............................................................................................................ 9 5.5 NOTICE OF TERMINATION.............................................................................................. 9 M 1.0 PURPOSE 1.1 Regulatory Background Operators of construction activities disturbing 10,000 square feet (2,500 sq. feet in Bay Act areas), and from smaller sites that are part of a larger, common plan of development are authorized to discharge storm water runoff to surface waters within Virginia under the General Permitfor Discharges of Storm water Management Program (VSMP) and the Virginia Storm water Management Act. The General Permit is regulated by the Virginia Department of Environmental Quality (DEQ). Permittees must submit a VSMP General Permit Registration Statement and prepare a Storm water Pollution Prevention Plan (SWPPP). Copies of both documents must be kept on -site during construction. In accordance with the General Permit, the purpose of the SWPPP is to identify potential sources of pollution that may affect the quality of storm water discharges from the construction site and to describe and ensure the implementation of practices that will be used to reduce pollutants in storm water discharges from the construction site. This SWPPP is effective beginning on the submission date of the VSMP General Permit - Discharges of Storm water from Construction Activities (VAR10) Registration Statement. 1.2 Storm Water Pollution Prevention Plan Organization This storm water pollution prevention plan (SWPPP) has been prepared in accordance with requirements of the Virginia permit. It is to be included in the specifications for the construction project of the Clover Lake Dam Repair, consequently making the construction plans (Sheets 9 of 9, by Froehling & Robertson, Inc., dated December 31, 2020) part of the SWPPP. M 2.0 FACILITY DESCRIPTION 2.1 General Clover Lake dam is a Significant Hazard Dam that was constructed for recreational purposes. It is situated on Little Ivy Creek in line with Emerson Drive and approximately 1.0 mile North West of Ivy, Virginia. The proposed spillway project is designed to safely pass the 100 year flood event with additional freeboard to the top of dam elevation of 499.0 feet. This project consists of design elements including construction of a concrete spillway chute. The current auxiliary spillway does not have sufficient capacity to pass the spillway design flood (SDF). The SDF is equal to the 100 year storm. The current spillway also does not have adequate stability under the SDF loading so a spillway upgrade project is required. 2.2 Drainage System A description of the project site drainage system is included with the Erosion and Sediment Control narrative in the project construction plans. 2.3 Site Description Existing Site Conditions: Clover Lake dam has a 2.48 square mile drainage area upstream of the impoundment that primarily consists of forested and open areas. The project area is approximately 0.50 acres and consists of the excavation for the installation of the new spillway and repair of the eroded embankment. The cut and fill is balanced on site so no excess or borrow soils are anticipated for the grading operations. Approximately 0.5 acres will be disturbed for this project. A VSMP Permit will be required. Project Description The auxiliary spillway will remain in the center portion of the dam and be constructed from reinforced concrete and include a box culvert under the roadway. The inlet will be a 42 foot long concrete sill for the control section setting the normal pool elevation. The passage under the road will be a 12 ft x 6 ft box culvert. Downstream the spillway chute will flare from 12 feet wide to 36 feet terminating into an energy dissipation apron and rip rap. The spillway channel sides will be vertical and the dam top will not be raised. The principal spillway tower and conduit will be abandoned with cement grout and a new siphon will be added for a bottom drain. This project will commence in Summer 2021 and is expected to be substantially complete in the Fall. The project will disturb approximately 0.5 acres of area. The existing rip rap channel will be removed for a net reduction of impervious area. Adjacent Properties: There are residential parcels adjacent to both sides of the dam with the homes set well back from the water. Upstream there are many other private residences surrounding the lake. The finish floor of one residence on the upstream limit of the lake is below the existing 100 year flood level. Conditions at this residence will be improved since this project lowers the 100 year flood elevation. Access to the lake and dam from Rte. 250 in Ivy, VA is north on West Leigh Drive to Kingston Road then left on Emerson Drive that crosses the dam. Clover Lake is upstream of the project and outfalls into Little Ivy Creek then Ivy Creek and eventually the Rivanna Reservoir. The drainage areas of Clover Lake Dam and Ivy Creek are primarily forested and open fields. Off Site Areas: Grading operations are expected to use available on site materials. There is no excess excavated earthen material. The owner's engineer shall provide approved Erosion and Sediment Control Plan and all necessary permits. Vegetative and construction debris will be hauled to an approved disposal area offsite. The contractor shall be responsible for final stabilization. Soils: The project area is located in Albemarle County, Virginia. Available geologic references (Geologic Map of Virginia,1993) report that the site lies within the Piedmont and Blue Ridge physiographic provinces. Elevation ranges from 250 feet where the Rivanna River and the James River leave the county to 3,250 feet at the summit of Loft Mountain. The Piedmont province makes up about 82 percent of the county. It is well dissected, by many small streams and rivers that flow in narrow, meandering valleys. The landscape is mostly gently sloping to moderately steep, but in places it is steep. Along the lower tributaries of the major streams, entrenchment has been rapid and bluffs and V-shaped valleys are common. The walls of the valleys are steep, and they rise abruptly from the flood plains. This province is broken in places by long, low hills and mountains. These include Ragged Mountain, Dudley Mountain, Fan Mountain, Bucks Mountain, Piney Mountain, and Southwest Mountain. Elevation ranges from 1,200 feet to 2,400 feet in these mountains. The low hills range from 600 to 1,200 feet in elevation. The smoothest relief in the Piedmont province is east of Southwest Mountain. The elevation ranges from 250 to 600 feet. Most of the soils are well drained throughout the Piedmont, but a few poorly drained soils are along streams, on toe slopes, and in a few saddles. The Blue Ridge province makes -up most of the western part of the county and is only 18 percent of the total land area. It is steep and rugged. It has been strongly dissected by many intermittent and permanent streams that have cut deep, narrow valleys bordered by steep rocky slopes -and narrow ridges. Slopes are moderately steep to very steep. Elevation ranges from about 1,200 feet to 3,250 feet. The soils are stony, shallow to deep, and well -drained to excessively drained. The rocks of Albemarle County are igneous, sedimentary, and metamorphic. Critical Areas: The most critical area is in the auxiliary spillway alignment between the top of dam and the stream below. The potential for erosion during construction will be managed with a clean water bypass and silt fence downstream of any disturbed areas. The spillway will be stabilized with concrete and rip rap. Storm Water Runoff: The dam's auxiliary spillway was designed with a concrete surface and sized to safely pass the spillway design flood and meet all other DCR Dam Safety guidelines. The new impervious area is the concrete spillway section which replaces the broad area of grouted rip rap resulting in a net reduction of impervious area. The decrease in impervious area satisfies the pollutant runoff reduction required for the project. The lake will be lowered several feet below normal pool until the new concrete for the spillway channel has cured. This will prevent the normal upstream rain events from damaging exposed areas during construction. In addition a construction emergency action plan (EAP) will be developed. The construction EAP will specify measures to further lower the lake in preparation for larger storm events and ensure any flows are allowed only on protected areas. The lake is lowered by cutting down the tower inlet until the siphon is installed and then it may be used to control the lake level. For normal daily flows from the lake drainage area will pass through the existing principal spillway. Potential pollution sources on this project site include the use of concrete materials, vehicle fueling, storage of equipment maintenance fluids, and sanitary waste facilities. 2.4 Construction Project Site Maps All information required on the site map is included on the plans for each construction activity. 3.0 NON -STORM WATER DISCHARGES Any non -storm water discharges must be in conformance with any applicable federal, state, and/or local laws, statutes, ordinances, rules, and regulations. The appropriate Federal, state and/or local regulatory agencies, including the Owner as required or as requested shall be notified immediately of any petroleum product, fuel or hazardous materials leak, spill, release, or other unauthorized environmental discharge occurring on the property. 3.1 Applicable laws All persons on the Owner's property, whether tenant, lessees, sub lessee, contractors, vendors or otherwise, shall comply with, at all times, all Federal, state and local laws, statues, ordinances, Rules and Regulations relating to environmental, health, safety, contamination and pollution matters ("environmental, health and safety law(s)"). 3.2 Handling and Disposal of Hazardous Materials All persons handling, storing or disposing of any hazardous material, hazardous waste or solid waste (As defined by all related environmental, health and safety laws, as amended from time to time) at the property must follow all applicable regulations including, but not limited to, those regulations which require proper identification, storage, containment and labeling of hazardous materials and/or wastes. Notifications of hazardous materials and/or waste generation must be made to the appropriate Federal, state and/or local regulatory agencies, including the Owner as required or as requested. Proper record keeping procedures, as required under any of the applicable regulations, must be maintained and made available for inspection by the Owner upon request. Hazardous materials and/or wastes must be disposed of only at permitted treatment, storage, and disposal facilities. 3.3 Notice, Response, and Remediation of Hazardous Materials Incidents The appropriate Federal, state and/or local regulatory agencies, including the Owner as required or as requested shall be notified immediately of any petroleum product, fuel or hazardous materials leak, spill, release or other unauthorized environmental discharge occurring on the property. In the event of a leak, spill, or release, the Contractor shall immediately initiate the proper remediation response. If the Contractor fails to respond in accordance with applicable local, state, and federal requirements, then the Owner will initiate remediation procedures. All persons responding to such leak, spill, release, or other unauthorized environmental discharge shall have received all required training and possess all required equipment for such remediation activities under applicable environmental, health, and safety laws. To the extent that notification of a leak, spill, release, or other unauthorized environmental discharge at the project is required under any environmental, health and safety law to any Federal, state or local agency, the same notice shall also be provided contemporaneously to the Owner. If the Owner initiates remediation activities for hazardous materials incidents due to a failure by any persons to appropriately respond to and remediate any unauthorized discharge then the responsible person shall be charged at a rate of 200% of the cost for remediation and/or compliance. 3.4 Notice of Environmental Permitting To the extent any person operating at the property is required to apply for and obtain any environmental permit, license or approved plan (e.g., oil discharge contingency plans) from any Federal, state or local agency for such operation, the Owner shall be contemporaneously advised of such application and provided a copy thereof and a copy of any issued/approved permit, license, plan, or any change or update thereto. 3.5 Underground Storage Tanks All persons owning or operating underground storage tanks at the property must comply with all applicable environmental, health and safety laws related thereto, including Virginia State Water Control Board Regulations VR 680-13-02 and VR 680-13-03, as amended from time to time. 3.6 Above Ground Storage Tanks All persons owning or operating aboveground storage tanks at the property must comply with all applicable environmental, health, and safety laws related thereto, including but not limited to pertinent and applicable provisions of National Fire Protection Association ("NFPA") Standards 30 and 407 and Virginia State Water Control Board Regulation VR 680-14-07 (oil discharge contingency plan), all as may be amended from time to time. 3.7 Right to Know All persons operating at the property must comply with applicable provisions of the Emergency Planning and Community Right -To -Know Act of 1986 (EPCRA) and all other environmental, health, and safety laws with respect to hazardous chemical inventory and release reporting, notifications to the appropriate government agencies, including the Owner, and compliance with communication requirements to the public and employees. 3.8 Penalties Failure by any persons to make any required notification, to remediate any unauthorized environmental discharge, to comply with all federal, state and local laws, statues, ordinances, Rules and Regulations relating to environmental, health, safety, contamination and pollution matters, or to apply for and receive any permit required under any of these environmental regulations shall result in the Owner enforcing this failure as a violation of these Rules and Regulations and in the issuance of an administrative penalty. 3.9 Responsibility of the Owner All persons other than the Owner shall be liable to and indemnify the Owner for payment of any fines or penalties levied against the Owner for alleged violations of any environmental, health or safety laws arising out of the actions of such persons causing the violation of such laws and shall be liable and indemnify the Owner for the cost or fee of any cleanup or remediation incurred by the Owner and related thereto. 4.0 STORM WATER MANAGEMENT CONTROLS 4.1 Best Management Practices for Construction Activities Best Management Practices (BMP's) have been selected by the design engineer and are included on the plans for this construction project. Each BMP shall be installed and maintained in accordance with the plans and specifications. The erosion and sediment control plan approved by local officials shall be included as part of this Storm water Pollution Prevention Plan (SWPPP). 4.2 Erosion and Sediment Control Soil erosion and sediment control measures shall be in accordance with the Virginia Erosion and Sediment Control Handbook (VESCH), Third Edition, dated 1992. The erosion and sediment control measures shown on the plans are considered minimal, "and early operational" steps to avoid point source release of deposits from the construction site. Additional erosion and sediment control measures may be required, or deemed necessary, during the course of the project time and work calendars, and in response to recognition, the contractor shall pursue proper course and address the need with proper measures. Specific types of erosion and sediment control are described in detail in the plans and specifications for each construction project. Maintenance of these measures is the responsibility of contractor until such time that the site is stabilized and the temporary erosion and sediment control measures can be removed. In accordance with state requirements, project operations will be supervised [at all times] by a contractor supervisor who has completed course studies and maintains a current State E&S Certification Card. 4.3 Post Construction Storm Water Management Any storm water management measures installed during construction to remain in place after permanent soil stabilization, such as detention ponds or velocity dissipation devices, are described in the plans and specifications. Maintenance of these measures is the responsibility of the contractor until final stabilization of the site. Conversion of Temporary Structures or Facilities to Permanent Facilities is specified in the Project Contract Documents, and this work shall be pursued by the contractor accordingly. 5.0 MONITORING AND DOCUMENTATION 5.1 Site Inspections As a minimum, site inspections shall be performed by the contractor on a weekly basis during dry weather and before and after storm events. These inspections shall be performed as part of a regular construction inspection program and reports of each inspection shall be kept. Items requiring attention, maintenance, or repair will be noted and corrected. Copies of the inspection reports will be retained by the contractor for a period of at least three (3) years from the date of final site stabilization. 5.2 Personnel Designation The Director or their designated representative is designated as the construction SWPPP coordinator for all activities at the property. The contractor's Project Superintendent will serve the role as the "Certified Responsible Person" with regard to field operations. This role will require prompt and immediate attention and action to concerns or issues that are recognized and forwarded to the field by the Director, and/or the Engineer. 5.3 SWPPP Content Review SWPPP elements will be modified as required. Elements specificto each construction project can be modified by the design engineer within the permit requirements. The SWPPP will also be amended at any time it is found to be not adequately addressing conditions of the Virginia DEQ/DCR requirements. The contractor will serve to assist the Director and the Engineer in recognizing necessary modifications, and making recommendations for corrective actions. The Engineer will review and make recommendations as to the [technical] need and suitability of proposed modifications or corrective actions [per the contract]. 5.4 Certification The contractor will retain the VSMP General Permit - Discharges of Storm water from Construction Activities (VAR10) Registration Statement. The contractor will be responsible for understanding and acknowledging the Project SWPPP requirements [per the contract]. 5.5 Notice of Termination When the site has been finally stabilized and all storm water discharge from construction activities that are authorized by this permit are eliminated, the contractor shall submit a Notice of Termination to DEQ. The terms and conditions of this SWPPP shall remain in effect until a completed Notice of Termination is submitted.