400 likes | 596 Views
ELEMENTS OF AN EFFECTIVE SEDIMENT CONTROL PLAN DESIGN APPROACH- THE BASICS. Issued May 2009. OBJECTIVE. THE BEST EROSION, SEDIMENTATION AND POLLUTION CONTROL PLANS. STEPS TO AN EFFECTIVE EROSION, SEDIMENTATION & POLLUTION CONTROL PLAN. Project requirements Project/resources description
E N D
ELEMENTS OF AN EFFECTIVE SEDIMENT CONTROL PLAN DESIGN APPROACH- THE BASICS Issued May 2009
OBJECTIVE THE BEST EROSION, SEDIMENTATION AND POLLUTION CONTROL PLANS
STEPS TO AN EFFECTIVE EROSION, SEDIMENTATION & POLLUTION CONTROL PLAN • Project requirements • Project/resources description • Data collection • Data interpolation • Plan preparation • Implementation • Operations & maintenance
THE BASICS • REQUIREMENTS OF A GOOD PLAN • COMPONENTS OF A GOOD PLAN
REQUIREMENTS • MEET REQUIREMENTS OF GESA • MEET REQUIREMENTS OF GENERAL PERMIT • MEET FEDERAL REGULATIONS • MEET LIA REQUIREMENTS
NPDES Requirements DESIGN A 3 PHASE ES&PC PLAN • Initial Phase (Clearing & Grubbing) • Intermediate Phase (Grading & Drainage) • Final Phase (Final Stabilization)
EXAMPLE PLAN CLEARING PHASE • Establish clearing limits • Locate state waters/wetlands • Establish perimeter protection • Provide the required initial storage • Observe sensitive soil areas • Establish construction exits • Define special BMP requirements • Generation of dust shall be eliminated or minimized to the maximum extent practical
CLEARING PHASE • Define sub phases if required • Establish full implementation of sediment ponds • Make adjustments if required • Define critical work zones • Establish locations of concentrated & sheet discharge • Maintain full coordination between the contractor, design professional and the regulatory inspector regarding project sequence
SEDIMENT PONDS • Design as per requirements based on sub basin size, soils, etc. • Divert offsite flows around disturbed areas and sediment basins if possible • Provide construction details as necessary
CLEARING PHASE • Prior to the land disturbing activity, the contractor should schedule a preconstruction meeting with the area site development inspector. • No staging areas, material storage, concrete wash out areas, or debris burn and burial holes should be located within 500 ft. of designated tree protection areas or stream buffers. • A copy of the approved land disturbance plan and permit shall be present on the site at all times. Post on day one.
CLEARING PHASE • Prior to commencing land disturbance activity, the limits of land disturbance should be clearly and accurately demarcated with stakes, ribbons, or other appropriate means. The location and extent of all authorized land disturbance activity should be demarcated for the duration of the construction activity. No land disturbance shall occur outside the approved limits indicated on the approved plans.
CLEARING PHASE • Prior to any other construction, a stabilized construction entrance/exists, all perimeter controls and sediment storage devices shall be constructed at each point of entry to or exit from the site or onto any public roadway as shown on plans. • Immediately after the establishment of construction entrance/exits, all perimeter erosion control and stormwater management devices shall be installed as shown on the clearing phase ES&PC Plan.
CLEARING PHASE • Silt fence should be installed at the perimeter of the disturbed area as shown on the plan. Silt should be removed when accumulation reaches ½ height of the barrier. The perimeter silt fence should be inspected weekly and after qualifying rain events for any failures. Any failures of said fencing should be repaired immediately.
CLEARING PHASE • Inlet sediment protection measures shall be installed on all existing storm structures as shown on the plan. • Stone check dams shall be installed in areas of concentrated flows as shown on the plan.
CLEARING PHASE • Tree protection fencing and stream buffer limits should be installed prior to the start of any land disturbance activity and maintained until final landscape is installed. The tree protection fencing should be inspected daily. Any failures of said fencing should be repaired immediately.
CLEARING PHASE For common developments that begin construction activity after the effective date of this permit, the primary permittee and tertiary permittee(s) must retain the design professional (DP) who prepared the ES&PC Plan, except when the permittee has requested in writing and EPD has agreed to an alternate DP, to inspect the installation of the initial sediment storage requirements and perimeter control BMPs which the DP designed within seven (7) days after installation.
CLEARING PHASE (cont) • The DP shall determine if these BMPs have been installed and are being maintained as designed. The DP shall report the results of the inspection to the permittee within seven (7) days and the permittee must correct all deficiencies within two (2) business days of receipt of the inspection report from the DP unless weather related site conditions are such that additional time is required. Gar 100003 Part IV.A.5.
CLEARING PHASE • After approval of the initial erosion control installation, the contractor may proceed with clearing and grubbing activities. As clearing permits, the contractor shall construct temporary sediment ponds and diversion dikes as shown on the clearing phase plan to control erosion and stormwater runoff.
CLEARING PHASE • Mulch or temporary grassing shall be applied to all exposed areas within 14 days of land disturbance (LIAs may require ground cover be applied in less 14 days).
CLEARING PHASE • Permittees shall inspect control measures as required by NPDES • Erosion control measures will be maintained at all times. If full implementation of the approved plan does not provide for effective erosion control, additional erosion and sediment control measures shall be implemented to control or treat the sediment source as directed by the onsite inspector or design professional.
CLEARING PHASE • Failure to properly install, operate, or maintain all erosion control measures can result in all construction being stopped on the job until such measures are corrected back to the approved erosion control plans, i.e., mandatory stop work order!
GRADING & DRAINAGE PHASE • Establish diversion dikes • Define mulching, temporary stabilization measures • Define critical work zones • Define special BMPs/methods • Maintain communication with contractor/inspector • Generation of dust shall be eliminated or minimized to the maximum extent practical
GRADING & DRAINAGE PHASE • During construction, the contractor should maintain careful scheduling and performance to ensure that land stripped of its natural ground cover is exposed only in small quantities and therefore limited durations, before permanent erosion protection is established.
GRADING & DRAINAGE PHASE • Maintain full coordination with the design professional, contractor and regulatory inspector at all times regarding project sequence. • Earthwork operations in the vicinity of stream buffers should be carefully controlled to avoid dumping or sloughing into the buffer areas.
GRADING & DRAINAGE PHASE • Sediment shall not be washed into inlets. It shall be removed from the sediment traps and disposed of and stabilized so that it will not enter the inlets again.
GRADING & DRAINAGE PHASE • All slopes steeper than 2.5:1 and with a height of 10 ft. or greater, and cuts and fills within stream buffers, shall be stabilized with appropriate erosion control matting or blankets. • Appropriate silt fence shall be placed at the toe of all dirt stock pile areas. • Inlet sediment protection measures shall be installed on all storm structures as they are constructed.
GRADING & DRAINAGE PHASE • Storm drain outlet protection shall be placed atall outlet headwalls as soon as the headwall is constructed. • Stone check dams shall be installed in areas of concentrated flows as shown on the plan. • Mulch or temporary vegetation shall be applied to all exposed areas within 14 days of land disturbance.Note local requirements
GRADING & DRAINAGE PHASE • Sediment and erosion control measures should be checked weekly and after each qualifying rain event. Each device is to be maintained if sediment accumulation has reached ½ the capacity of the device. 1/3 of the storage capacity of temporary sediment basin and retrofit structures
GRADING & DRAINAGE PHASE • The construction exit shall be maintained in a condition which will prevent track or flow of mud onto public right-of-way. This may require periodic top dressing with 1.5”-3.5” of stone, as conditions demand. All materials spilled, dropped, washed or tracked from a vehicle onto public roadway or into storm drain must be removed immediately.
GRADING & DRAINAGE PHASE • Define sub phases as required • Redefine sedimentation ponds as required • Provide special details as required • Merge sedimentation ponds with stormwater management facilities • Utilize special BMPs as required
FINAL PHASE • Final vegetative measures • Final structural measures • Final stormwater systems
FINAL PHASE • Maintain full coordination with the design professional, contractor and regulatory inspector at all times regarding project sequence. • Sediment shall not be washed into inlets. It shall be removed from the sediment traps and disposed of and stabilized so that it will not enter the inlets again. • Mulch or temporary grassing shall be applied to all exposed areas within 14 days of land disturbance. • Implement final stabilization.
FINAL PHASE • The contractor shall maintain all sediment ponds and erosion control measures until permanent ground cover is established. Sediment shall be cleaned out of the ponds when it reaches one third full. • After curbing, graded aggregate base, and pavement have been installed, all inlet sediment traps on single and double wing catch basins along with any curb inlets shall be removed and replaced with curb filter inlet protection.
IMPORTANT COMPONENTS • Notes – per phase • Schedule • Certifications • Sediment pond design • Details