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1
Field Application Training for Erosion and
Sediment Control BMPs on Caltrans Construction
Sites
CTSW-OT-06-137.17.1
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Introduction

• Class Handouts
• Sign-in Sheet
• Level II Assessment
• G0C100
• Date
• Breaks / Lunch

3
Course Handbooks

• Caltrans Storm Water Quality Handbooks and
  Manuals
• Construction Site BMPs Manual
• Guidance for Temporary Soil Stabilization
• Get Manuals online at http//www.dot.ca.gov/hq/con
  struc/stormwater/manuals.htm or hard copies are
  available from Caltrans Publications

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Introduction Your Facilitators

• Who are we ?
• What is our background?

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Introduction About You

• Who are you?
• What is your storm water background?
• What do you want to learn from this class?

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Introduction Class Objectives
After successful completion of the course, you
should be able to

• Understand the types and causes of erosion
• Understand which processes influence erosion
• Understand which temporary BMPs are used to
  control erosion
• Understand erosion and sediment control planning
  strategies
• Be prepared to review and inspect SS and SC BMPs
  as designed and implemented in the field

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Introduction

• Key Point
• This course is about Temporary BMPs
• Defined as Interim control measures which are
  installed or constructed to control soil erosion
  and which are not maintained after project
  completion
• As opposed to..

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Introduction

• Permanent BMPs
• Defined as measures which are installed or
  constructed to control soil erosion and which are
  maintained after project completion

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Introduction

• Course Highlights
• Introduction
• Planning for Erosion and Sediment Control
• Erosion Control BMP Planning and Implementation
• Sediment Control BMP Planning and Implementation
• Class Exercise
• Field Demonstration of BMPs

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Introduction

• Sediment is the number one pollutant of the
  nations rivers and lakes

• An estimated 80 Millions Tons of solids are
  discharged annually from construction sites into
  receiving waters

According to the EPA
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Introduction

• On a unit basis, construction sites export
  sediment at 20 to 1,000 times the rates of other
  land uses.

According to the EPA
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Introduction

• Temporary soil stabilization can be the
  single-most important factor in reducing erosion
  at construction sites.

NPDES General Construction Permit
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Introduction

• Caltrans Manual

Guidance for Temporary Soil Stabilization Compl
eted July 2003

• Aid for planning, selection, and implementation
  of BMPs for soil stabilization

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SWRCB / NPDES - General Construction Permit

• Rainy Season
• At a minimum, the discharger/operator must
  implement an effective combination of erosion and
  sediment control on all disturbed areas during
  the rainy season
• The discharger shall consider surface
  stabilization measures such as covering with
  mulch, temporary seeding, soil stabilizers,
  binders, fiber rolls or blankets, temporary
  vegetation, permanent seeding, and a variety of
  other measures.

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SWPPP / WPCP

• Contractor Selected BMPs
• SWPPP Preparation Manual
• 500.3.4 Soil Stabilization
• 500.3.5 Sediment Controls
• WPCP
• 30.1.1 Soil Stabilization
• 30.1.2 Sediment Control

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Manuals

• Construction Site BMP Manual 2003
• NEW Guidelines for the selection and
  implementation of construction site BMPs
• Rainy Season / Rainfall Area Definitions
• Procedures for Rainfall Area 7
• BMP Placement on Slopes
• SS and SC Requirements for DSAs

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Construction BMP Practices Manual

• Soil Stabilization and Sediment Control
  Requirements

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Rainy Season Dates

• Three distinct precipitation zones based on
  season and variability of rainfall patterns

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Area Definition

• Seven distinct areas based on location and
  elevation

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Non-Active DSAs

• Soil stabilization requirements for non-active
  disturbed soils areas based on season and slope
  inclination and length

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Active DSAs

• Soil stabilization requirements for active
  disturbed soils areas based on season and slope
  inclination and length

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What is Erosion and Sedimentation

• Soil erosion is the process by which soil
  particles become detached by water, wind, or
  gravity and are transported from their original
  location.

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What is Erosion and Sedimentation

• Sedimentation is the deposition of the eroded
  material

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Types of Erosion

• Splash Erosion
• Sheet Erosion (Overland Flow)
• Rill Erosion
• Gully Erosion
• Channel Erosion

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Splash Erosion

• Rain drops striking bare soil directly
• Detaches soil particles
• Particles can then be transported by the action
  of water and/or wind

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Sheet Erosion (Overland Flow)

• The removal of a uniform thin layer of soil by
  raindrop splash or water run-off
• Surface film of water 1/16 1/8 deep
• This process may occur unnoticed on exposed soil
  even though raindrops are eroding large
  quantities of soil
• This process eventually becomes more dramatic via
  the formation of rills and gullies

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Rill Erosion

• Shallow surface flows that become condensed
• Increased velocity and turbulence.
• Well-defined tiny channels
• The rate of rill erosion can be approximately 100
  X greater than sheet erosion

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Gully Erosion

• Accumulating runoff becomes concentrated and
  forms small rills throughout the soil
• Several rills may form throughout a slope and
  eventually may join together to form Gullies
• The rate of gully erosion can be approximately
  100 X greater than rill erosion

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Channel Erosion

• Results from increased volume, velocity and or
  duration of flow, and concentration of flow -
  primarily from increased impervious surfaces.
• Channel erosion occurs in areas where
  tributaries, storm drains and or culverts flow
  into unprotected channels

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Sedimentation / Turbidity

• Is solid particulate matter, that is in
  suspension, is being transported (Turbidity), or
  has been moved from its site by air, water,
  gravity or ice and has settled elsewhere
  (Sedimentation)

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• Course Highlights
• Introduction
• Planning for Erosion and Sediment Control
• Selection of BMPs For Erosion Control
• Selection of BMPs For Sediment Control
• Field Demonstration of BMPs

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Planning for Erosion Control

• To effectively stabilize Disturbed Soil Areas
  (DSAs) proper planning, selection and
  implementation of soil stabilization BMPs is
  necessary

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Planning Considerations

• Rainy Season
• Site Evaluation
• Scheduling
• Lead time for materials and equipment
• Weather Tracking
• Water Pollution Control Strategies
• Soil Preparation

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Rainy Season

• Review and evaluate soil disturbing activities
  during the rainy season
• Be aware of when and how much precipitation could
  potentially fall during storm events

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Site Evaluation

• Flow Conditions
• Slope Inclination and Length
• Soil Properties
• Surface area
• Atmospheric Condition
• Accessibility of Equipment
• Duration of Needs

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Site Evaluation - Flow Conditions

• Determine the types of flows which will impact
  the DSA of the construction site

• Sheet Flow
• Channelized Flow
• Run-on
• Run-off

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Site Evaluation - Slope Inclination and Length

• Slope Inclination
• Is the gradient of the face of the slope
• Slope Length
• Is measured or calculated along the continuous
  incline surface

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Site Evaluation - Soil Properties

• Soil Composition
• Classification of soil grain size, shape and
  mineralogy
• Shear Strength and Density
• Shear strength is the resistance to sliding from
  one mass of soil to another
• Density is the percent of void space in the soil
• Permeability
• Measure of how fast water can move through the
  soil
• Soil Chemistry
• The makeup of the soil
• Geological Features
• Subsurface geology

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Site Evaluation - Surface Area

• Small
• Equal to or less than 1 acre
• Medium
• Between 1 and 5 acres
• Large
• Greater than 5 acres

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Site Evaluation - Atmospheric Conditions

• Atmospheric conditions may limit the type of soil
  stabilization applied to disturbed soil areas

• Temperature
• Moisture and Humidity
• Wind

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Site Evaluation - Accessibility of Equipment

• Access to DSA may limit soil stabilization
  equipment from reaching areas

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Site Evaluation - Drainage

• It is essential to understand site run-off,
  run-on dynamics and control the drainage.

Caused this gully
Runoff here
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Site Evaluation - Duration of Need

• The length of time that a DSA will need to be
  protected should be considered

• Less than or equal to 3 months
• Between 3 and 12 months
• Greater than or equal to 12 months

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What can this site teach us?

• Incorrectly applied erosion control can actually
  increase erosion
• For example Silt fence should not be installed
  up and down slope
• Fiber rolls may have been used to break-up slope
  length

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Scheduling

• Lead time for obtaining materials and equipment
  to install the BMP is critical
• Consider
• Delivery time
• Installation time
• Effective lifespan
• Cost

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Weather Tracking

• Designate a person to monitor the forecast for
  probability, duration and expected intensity

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Erosion Control Strategies

• Erosion Control vs. Sediment Control
• Prevent storm water contact with the construction
  site
• Limit amount of disturbed soil areas (DSAs)
• Protect (DSAs) from erosion
• Minimize sediment in storm water before discharge
• Prevent storm water contact with other pollutants

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Erosion Control

• Any practice that protects the soil surface and
  prevents the soil particles from being detached
  by rainfall or wind.
• Erosion control, therefore, is a source control
  that treats the soil as a resource that has value
  and should be kept in place.

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Sediment Control

• Any practice that traps the soil particles after
  they have been detached and moved by wind or
  water.
• Sediment control measures are usually passive
  systems that rely on filtering or settling the
  particles out of the water or wind that is
  transporting them.

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Which are More Effective?

• Erosion controls are preferred
• keep the soil in place
• enhance the protection of the site resources
• When possible, use erosion controls as the
  primary protection, with sediment controls as a
  secondary system.

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Prevent Storm Water Contact With The Construction
Site

• Storm water from the sky - Rainfall
• Storm Water from adjacent areas - Run-on

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Prevent Storm Water Contact With The Construction
Site

• A BMP that is practicable to protect DSAs from
  rainfall is
• Scheduling

Rainy Season
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Limit the Amount of DSA

• Limit the amount and duration that DSA are
  exposed to rainfall impact, run-on and run-off
  and wind

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Protect Disturbed Soil Areas From Erosion

• BMPs practicable to protect DSAs from run-on
  are
• Earth dikes/drainage swales and lined ditches
• Sandbag Barriers

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Protect Disturbed Soil Areas From Erosion

• BMPs to protect DSAs from erosion are
• Temporary soil stabilization
• Top of slope dikes
• Slope drains
• Gravel bag berms or fiber rolls

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Minimize Sediment In Storm Water Before Discharge

• Sediment Barriers
• Silt Fence
• Sandbag barrier
• Straw bale barrier
• Fiber Rolls
• Gravel Bag Berm
• Sediment/Desilting Basins and Sediment Traps
• Site Containment

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Soil Preparation

• Proper preparation of the soil is necessary prior
  to the application of soil stabilization
  materials

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Soil Preparation
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Caltrans Evaluationof SS SC BMPs
Responsibility of Caltrans to review

• SWPPP / WPCP
• CPM Schedule (Critical Path Method)
• Rainy Season Implementation Plan
• Identify Active / Non-Active Areas
• Verify Quantities of Materials
• Inspection

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Caltrans Evaluationof SS SC BMPs

• SWPPP / WPCP
• Review contractors chosen SS SC BMPs
• Review Water Pollution Control Drawings (WPCDs)
• Review CPM schedule

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Caltrans Evaluationof SS SC BMPs

• Review Rainy season implementation plan
• Schedule of implementation
• 20 days prior to the rainy season
• Dates when SS SC will be 25, 50, 100
  completed
• Quantity of material needed
• Sufficient quantities of SS maintained onsite
• SC materials equivalent to 10 of the installed
  quantities

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Caltrans Evaluationof SS SC BMPs

• Identify Active and Non-Active DSA
• Verify quantities delivered
• Inspect BMP installation