Design of Treatment BMPs for Projects

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Design of Treatment BMPs for Projects

• June 2003

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Course Objectives
Introduction

• To provide direction/guidance for designing
  Treatment BMPs in accordance with the Project
  Planning and Design Guide (PPDG)
• To provide design exercises for most common types
  of Treatment BMPs
• workgroup exercises
• solved examples

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Course Overview
Introduction

• This course is very hands-on for design
  principles for each type of Treatment BMP
• Students are expected to have previously attended
  PPDG training and have a working knowledge of
  Hydraulics.

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Initial Assessment Quiz
Introduction

• Please take 10 minutes to complete the Initial
  Assessment Quiz
• Provide your answers in pencil (blue or black ink
  OK) on the PRE side of the Scantron card

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Regulatory Framework
Introduction

• Clean Water Act (CWA) was enacted to restore and
  maintain the integrity of the waters of the
  United States
• Under the CWA, the National Pollutant Discharge
  Elimination System (NPDES) Permits were
  established
• Caltrans has a statewide NPDES permit which
  covers both storm water and non-storm water
  runoff from both maintenance and operational
  activities and construction sites

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Caltrans Storm Water Management Plan (SWMP)
Introduction

• Caltrans Permit requires the Department to
  implement and maintain an effective SWMP
• Caltrans SWMP includes
• Procedures and practices to manage storm water
  quality
• Descriptions of major program elements
• Key implementation responsibilities and schedules
• A list of the approved BMPs

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Pollutants of Concern
Introduction

• Total Suspended Solids
• Nutrients
• Pesticides
• Particulate Metals
• Dissolved Metals
• Pathogens
• Litter
• Biochemical Oxygen Demand
• Total Dissolved Solids

PPDG Table 2-2, Page 2-7
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Caltrans Approved BMPs
Introduction

• Caltrans SWMP identifies permanent and temporary
  BMPs that have been approved for statewide
  application
• Four categories
• Design Pollution Prevention BMPs
• Treatment BMPs - this course
• Construction Site BMPs
• Maintenance BMPs

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Design Pollution Prevention BMPs
Introduction

• Design Pollution Prevention BMPs are
• Permanent Source Control BMPs to improve storm
  water quality after construction is complete
• Incorporated into all project designs

 
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Design Pollution Prevention BMPs
Introduction
PPDG Table A-1, Page A-1
 
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Design Pollution Prevention BMPs versus Treatment
Control BMPs

• Design Pollution BMPs are source control BMPs
  used to prevent pollutants from entering into
  Storm Water discharges
• Treatment BMPs are used to remove pollutants from
  storm water discharges. Usually provided in
  series with Design Pollution Prevention BMPs.

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Approved Treatment Control BMPs
Introduction

• Six types of treatment BMPs have been identified
  in the SWMP
• Biofiltration strips/swales
• Infiltration basins
• Detention devices
• Traction sand traps
• Dry weather flow diversion
• Gross Solids Removal Devices (GSRDs)

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Treatment Control BMPs
Introduction

• The approved treatment BMPs are considered to be
  technically and fiscally feasible.
• Caltrans has found these BMPs to be
  constructable, maintainable, and effective at
  removing pollutants.

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Treatment BMPDecision Tree T-1
Introduction
PPDG Page E-25
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Checklist T-1 Part 1 Questions
Introduction


PPDG Page E-26
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Site Specific Determination of Feasibility
Introduction

• Compliance with Siting Criteria
• Technical feasibility
• Regulatory, Legal and Institutional constraints

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Feasibility Assessment
Introduction

• Step 1 Gather data on tributary area and site
  characteristics
• Step 2 Determine Water Quality Volume (WQV),
  Water Quality Flow (WQF), and Design Storm that
  must be treated/conveyed
• Step 3 Calculate size of proposed BMP
• Step 4 Evaluate treatment BMP operational and
  siting considerations
• Step 5 Document process in Storm Water Data
  Report (see PPDG Appendix E)

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Questions