Inspecting for Water Pollution Control on Construction Sites

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Field Application Training for Erosion and
Sediment Control BMPs on Caltrans Construction
Sites
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Who Are We Who Are You?

• Part of Caltrans Overall Water Quality Program
• 5,000 Compliance
• Inspections All Caltrans Districts
• 5000 Trained
• 600 SWPPPs Prepared/Reviewed
• Specifications/Manuals Prepared

A

• Your Facilitators
• Joe Crea, CPESC, CPSWQ
• Ron Lamaster, CPESC
• Audience Introductions

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Why Are You Here?

• To learn about the types and causes of erosion
• To learn about factors which influence erosion
• To review planning strategies for erosion and
  sediment control BMPs
• To learn about BMPs implementation for erosion
  and sediment controls
• To review EC and SC BMPs implemented in the field

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What You Will Learn

• What are the causes and effects of erosion
• What factors influence the erosion process
• Planning for erosion and sediment control
  implementation
• How Best Management Practices are used for
  erosion and sediment control
• What BMPs should look like when properly
  implemented in the field

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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 that is
  discharged from construction sites

• 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 site 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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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 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
• 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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Caltrans 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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Manuals

• Construction Site BMPs Manual - 2003
• Guidelines for the selection and implementation
  of construction site BMPs
• Rainy Season / Rainfall Area Definitions
• Procedures for Rainfall Area 7
• BMP Placement on Slopes
• EC 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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Caltrans Manual

• Guidance for Temporary Soil Stabilization
• Guidance document that helps with the planning,
  selection, and implementation of BMPs for soil
  stabilization

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Erosion and Sedimentation

• 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.
• Sedimentation is the result of deposition
  (settling out) of the detached soil particles.

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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
• Detach soil particles
• Particles can then 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 2-3 mm 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

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Gully Erosion (Concentrated Flow)

• 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 rill erosion can be approximately 100
  X greater than sheet erosion and the rate of
  gully erosion can be approximately 100 X greater
  than rill erosion

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Channel Erosion

• Occurs when the equilibrium between the flow of
  water and friction of the soil surface is
  disrupted
• Results from increased volume, velocity and or
  duration of flow, concentration of flow or
  removal of vegetation
• Channel erosion occurs in areas where
  tributaries, storm drains and or culverts flow
  into unprotected channels

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Sedimentation

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

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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
• Limiting the Amount of Soil Exposure
• BMP Selection
• 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
• Drainage (303 (d) Water Bodies)
• 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 Strenght 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 0.4 Hectors (1 Acre)
• Medium
• Between 0.4 and 2 hectares (1 5 Acres)
• Large
• Greater than 2 hectares (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
  dynamics and control needs

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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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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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Limiting 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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Soil Preparation

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

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Caltrans Evaluationof SS EC BMPs

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

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

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