Transcript Level II Section 7a Design Planning May 2009

ELEMENTS OF AN EFFECTIVE
SEDIMENT CONTROL PLAN
PLANNING APPROACH
Level II: Introduction to Design
Education and Certification for Persons
Involved in Land Disturbing Activities
Issued May 2009
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TOOLS TO USE
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Site Survey
County Topo Maps
USGS Survey
Soil Survey
Soils Investigation
Wetlands Maps
Phase I Investigation
Recorded Plats
FEMA Flood Maps
Blue Book – GA Stormwater Manual
Manual for Erosion and Sediment Control in GA2
http://www.gaswcc.org/docs.htm
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WHAT CAN BE DETERMINED FROM
SOIL TYPES
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Available water capacity
Depth to bed rock
Depth to water table
Drainage
Erodibility
Fertility
Infiltration
Percolation rate
Permeability
Slope
Shrink-swell potential
Susceptibility to flooding
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PROJECT CONSTRUCTION ISSUES
• Project Location
• Required Predesign Site Visit
• Phasing
• Project Size
• Project Type
• Project Schedule
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REQUIRED PREDESIGN SITE VISIT
APPROVED RULE –
Plan preparer/design professional must
certify that a site visit by the plan preparer
(or their designee) has been conducted
prior to creation of the plan
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SITE VISIT CERTIFICATION ON PLANS
I certify under penalty of law that this plan was
prepared after a site visit to the locations
described herein by myself or my authorized
agent, under my direct supervision.
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Design Professional
Date
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SITE VISIT CHECKLIST
THINGS TO LOOK FOR –
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Existing vegetation – specimen trees, etc.
State waters potential
US waters potential
Flood plain
Springs
Soils conditions
Topography
Basin delineation/visual evaluation
Offsite drainage
Offsite/downstream conditions
Wetlands
Archaeological
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STATE WATERS
Any and all rivers, streams, creeks, branches,
lakes, reservoirs, ponds, drainage systems,
springs, wells and other bodies of surface or
subsurface waters, natural or artificial, lying
within or forming a part of the boundaries of the
state which are not entirely confined and
retained completely upon the property of a
single individual, partnership or corporation
(Ref. GESA)
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NOT JUST STATE WATERS
U.S. WATERS TOO…….
• 404 permits may be required (U.S. Clean
Water Act)
• Feds noted that much confusion may
exist related to utility and road
construction
• Reference EPA letter (appendix)
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STATE/US WATERS ISSUES
• While there may be some activities which
are exempt from state regulation, the
USACE recommends a developer
(permittee) contact them if any amount of
fill material may be placed in a water of the
U.S.
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U.S. WATERS GUIDELINE
• Projects impacting more than a 0.10 acre
of wetlands or 300 feet of stream will likely
require an individual Department of the
Army Permit.
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Minimum Requirements
• Stripping of vegetation, regrading and other
development activities shall be conducted in
such a manner so as to minimize erosion
• Cut and fill operations must be kept to a
minimum
• Development plans must conform to topography
and soil type, so as to create the lowest
practicable erosion potential
• Whenever feasible, natural vegetation shall be
retained, protected and supplemented
(Ref. O.C.G.A. 12-7-6)
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Minimum Requirements
• Disturbed soil shall be stabilized as quickly as
practicable
• Temporary vegetation or mulching shall be employed
to protect exposed critical areas during development
• Permanent vegetation and structural erosion control
measures must be installed as soon as practicable.
• Sediment in runoff water must be trapped by the use of
debris basins, sediment basins, silt traps or similar
measures until the disturbed area is stabilized
• Adequate provisions must be provided to minimize
damage from surface water to the cut face of
excavations or the sloping surfaces of fills
(Ref. O.C.G.A. 12-7-6)
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Minimum Requirements
• Cuts and fills may not endanger adjoining
property
• Fills may not encroach upon natural
watercourses or constructed channels in a
manner so as to adversely affect other
property owners
• Grading equipment must cross flowing
streams by the means of bridges or
culverts, except when such methods are
not feasible, provided, in any case, that
such crossings must be kept to a minimum
(Ref. O.C.G.A. 12-7-6)
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Minimum Requirements
• The disturbed area and duration of exposure to
erosive elements shall be kept to a practicable
minimum.
• Land disturbing activity plans for erosion and
sedimentation control shall include provisions for
control or treatment of any source of sediments
and adequate sedimentation control facilities to
retain sediments on site or preclude
sedimentation of adjacent waters.
(Ref. O.C.G.A. 12-7-6)
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PLAN CONCEPTS
• Adapt the plan to resources available
• When possible, fit the project into the
existing terrain
• Recommendations must be cost-effective
• The plan must be flexible
• Maintain open communication with
developer, contractors and local issuing
authority
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PLAN CONCEPTS
• Notes and instructions must be clear and
simple
• Timing and scheduling are very important
• Establish an effective maintenance
program
• Identify critical offsite areas
• Monitor impacts
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CONSTRUCTION SEQUENCING
• Plan sequence with contractor.
• Advise inspector/LIA of sequence at preconstruction meeting.
• Evaluate sequence during implementation.
• Make sequence revisions.
• Provide LIA/GA EPD/contractor
documentation of revised design.
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THREE PHASE CONSTRUCTION
• CLEARING PHASE (clearing & grubbing)
• GRADING PHASE (grading & temporary
vegetation)
• FINAL PHASE (stormwater management
& permanent vegetation)
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PERHAPS THE MOST IMPORTANT
STEP IS…..
TO UNDERSTAND HOW A SITE
ACCOMODATES RUNOFF IN PREDURING AND POST-CONSTRUCTION
CONDITIONS.
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