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Field Application Training for Erosion and Sediment Control BMPs on Caltrans Construction Sites.

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Presentation on theme: "Field Application Training for Erosion and Sediment Control BMPs on Caltrans Construction Sites."— Presentation transcript:

1 Field Application Training for Erosion and Sediment Control BMPs on Caltrans Construction Sites

2 2 Who Are We – Who Are You?  Your Facilitators –Joe Crea, CPESC, CPSWQ –Ron Lamaster, CPESC  Audience Introductions  Part of Caltrans’ Overall Water Quality Program - 5,000+ Compliance - Inspections …All Caltrans Districts - 5000+ Trained - 600+ SWPPPs Prepared/Reviewed - Specifications/Manuals Prepared A

3 3 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

4 4 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

5 5 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

6 6 Introduction  “An estimated 80 Millions Tons of solids are discharged annually from construction sites into receiving waters” According to the EPA  Sediment is the number one pollutant that is discharged from construction sites

7 7 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

8 8 Introduction  Temporary soil stabilization can be the single-most important factor in reducing erosion at construction sites. NPDES General Construction Permit

9 9 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.

10 10 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

11 11 Caltrans Handbooks  Caltrans Storm Water Quality Handbooks and Manuals –Construction Site BMPs Manual –Guidance for Temporary Soil Stabilization  Get Manuals online at or hard copies are available from Caltrans Publications

12 12 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

13 13 Construction BMP Practices Manual  Soil Stabilization and Sediment Control Requirements

14 14 Rainy Season Dates  Three distinct precipitation zones based on season and variability of rainfall patterns

15 15 Area Definition  Seven distinct areas based on location and elevation

16 16 Non-Active DSAs  Soil stabilization requirements for non-active disturbed soils areas based on season and slope inclination and length

17 17 Active DSAs  Soil stabilization requirements for active disturbed soils areas based on season and slope inclination and length

18 18 Caltrans Manual  Guidance for Temporary Soil Stabilization –Guidance document that helps with the planning, selection, and implementation of BMPs for soil stabilization

19 19 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.

20 20 Types of Erosion –Splash Erosion –Sheet Erosion (Overland Flow) –Rill Erosion –Gully Erosion –Channel Erosion

21 21 Splash Erosion  Rain drops striking bare soil directly –Detach soil particles –Particles can then transported by the action of water and/or wind

22 22 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

23 23 Rill Erosion  Shallow surface flows that become condensed  Increased velocity and turbulence.  Well-defined tiny channels

24 24 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

25 25 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

26 26 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

27 27  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

28 28 Planning for Erosion Control  To effectively stabilize Disturbed Soil Areas (DSAs) proper planning, selection and implementation of soil stabilization BMPs is necessary

29 29 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

30 30 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

31 31 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

32 32 Site Evaluation - Flow Conditions  Sheet Flow  Channelized Flow  Run-on  Run-off  Determine the types of flows which will impact the DSA of the construction site

33 33 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

34 34 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

35 35 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)

36 36 Site Evaluation - Atmospheric Conditions  Temperature  Moisture and Humidity  Wind  Atmospheric conditions may limit the type of soil stabilization applied to disturbed soil areas

37 37 Site Evaluation - Accessibility of Equipment  Access to DSA may limit soil stabilization equipment from reaching areas

38 38 Site Evaluation - Drainage  It is essential to understand site run-off dynamics and control needs

39 39 Site Evaluation - Duration of Need  Less than or equal to 3 months  Between 3 and 12 months  Greater than or equal to 12 months  The length of time that a DSA will need to be protected should be considered

40 40 Scheduling  Lead time for obtaining materials and equipment to install the BMP is critical  Consider: –Delivery time –Installation time –Effective lifespan –Cost

41 41 Weather Tracking  Designate a person to monitor the forecast for probability, duration and expected intensity

42 42 Limiting the Amount of DSA  Limit the amount and duration that DSA are exposed to rainfall impact, run-on and run-off and wind

43 43 Soil Preparation  Proper preparation of the soil is necessary prior to the application of soil stabilization materials

44 44 Caltrans Evaluation of SS & EC BMPs  SWPPP / WPCP  CPM Schedule  Rainy Season Implementation Plan  Identify Active / Non-Active Areas  Verify Quantities of Materials  Inspection

45 45  SWPPP / WPCP –Review contractors chosen SS & SC BMPs –Review Water Pollution Control Drawings (WPCDs) –Review CPM schedule

46 46  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

47 47  Identify Active and Non-Active DSA  Verify quantities delivered  Inspect BMP installation

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