UPDATE ON ODOTS L

1
UPDATE ON ODOTS LD MANUAL FOR POST-CONSTRUCTION
CONTROL BMPS

• Mike Wawszkiewicz, P.E.
• Hydraulic/BMP Specialist, Central Office
  Production

2
Introduction

• Topics
• Linear Transportation Post-Construction BMPs
• Differences from standard residential/commercial
  development
• Design Requirements
• Amount of Treatment
• ODOT Experiences
• Design, Construction, Maintenance Issues
• Maintenance and Permitting Responsibilities
• Whats next?

3
Introduction

• Magnitude of Permitting
• Per OEPA database of Construction General Permit
  Permittees
• ODOT has 660 permits
• To ensure a consistent application regarding
  post-construction BMPs for roadway projects, ODOT
  needed to have design guidelines

4
ODOT/Storm Water Acronyms

• BMP Best Management Practice
• CGP Construction General Permit
• EBW Enhanced Bankfull Width
• EDA Earth Disturbed Area
• ExT Exfiltration Trench
• LD Manual ODOT Location and Design Manual
• LPA Local Public Agency
• NOI Notice of Intent
• NPDES National Pollutant Discharge Elimination
  System
• OEPA Ohio Environmental Protection Agency
• SWPPP or SWP3 Storm Water Pollution Prevention
  Plan
• T - Treatment Percent
• TSEC Temporary Sediment and Erosion Control
• VBF Vegetated Biofilter
• WQf Water Quality Flow
• WQv Water Quality Volume

5
Linear Transportation BMPs

• Linear Transportation Projects vs. Standard Land
  Development
• Difficulty implementing BMPs listed in the
  Construction General Permit
• R/W limitations (Eminent Domain)
• Safety of the traveling public
• Linear nature results in crossing multiple
  watersheds (centralized BMP impossible)

Dangers of Ponded Water
Multiple Watersheds Crossed
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Linear Transportation BMPs

• Difficulty implementing BMPs listed in the
  Construction General Permit (cont.)
• Roadway improvements offer little ability to
  change alignment to allow easier BMP
  implementation. Not an option to relocate
  existing bridges and roads in most cases.
• Urban environments Highly developed areas with
  little room for storm water facilities

Henderson Road Bridge
7
Linear Transportation BMPs

• Rural Construction
• Options are limited
• Vegetated Biofilter
• Small Dry Detention Areas

• Urban Construction
• Options are very limited
• Manufactured Systems
• Exfiltration Trench
• Underground Storage

8
Linear Transportation BMPs

• Ohio EPA Construction General Permit for Storm
  Water Discharge (OHC000003)
• Part III.G.2.e Post-Construction Storm Water
  Management Requirements
• Transportation Projects ODOT LD Volume 2
• The construction of new roads and roadway
  improvement projects by public entities (i.e.,
  the state, counties, townships, cities, or
  villages) may implement post-construction BMPs in
  compliance with the current version (as of the
  effective date of this permit) of the Ohio
  Department of Transportations Location and
  Design Manual, Volume Two Drainage Design that
  has been accepted by Ohio EPA as an alternative
  to the conditions of this permit.

9
Linear Transportation BMPs

• ODOT and OEPA agreed that the following
  alternative BMPs can be used for linear
  transportation projects
• Manufactured System
• Vegetated Biofilter
• Exfiltration Trench

10
Linear Transportation BMPs

• Manufactured Systems Item 895
• Filtering devices that allow for treatment of a
  portion of the flow in a storm sewer

• Note off-line configuration

11
Linear Transportation BMPs

• Exfiltration Trench Item 835
• Pervious concrete layer at top allowing water to
  enter a 12 inch layer of filter material
• Standard Construction Drawing WQ-1.3

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Design Requirements

• ODOT Location Design, Volume 2
• Project Thresholds
• Earth Disturbed Area (EDA gt 1 acre)
• Routine Maintenance Projects are exempt
• Projects that do not change original line, grade
  and hydraulic capacity of the facility (i.e.
  resurfacing)
• EDA lt 5 acres
• List of maintenance activities in LD Vol. 2,
  Section 1200

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Design Requirements

• ODOT Location Design, Volume 2
• Project Classifications for Post-Construction
  Storm Water BMP Design
• Redevelopment vs. New Construction
• Redevelopment - 20 treatment required
• New Construction Treatment (T) required

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Design Requirements

• New Construction
• New Construction does not necessarily mean a
  brand new highway alignment. Any project where
  pavement is added outside the existing R/W
  resulting in a change in the runoff coefficient.
• The area within existing ODOT R/W is considered
  impervious area for the purpose of
  post-construction BMP calculations

Calculate Weighted Average of New Impervious vs.
Existing Impervious to determine amount of
treatment
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Design Requirements

• New Construction
• New construction projects allow for a reduction
  of treatment based on the weighted average of
  existing vs. new impervious area in a drainage
  area or for a project (Treatment Percent)

• A brand new alignment project would require 100
  treatment

16
Design Requirements

• What does New Construction mean for the amount of
  treatment required?
• Localized Treatment 100 treatment for a
  specific area of the project (Area must be equal
  to T x Project Earth Disturbed Area)
• or
• Project Wide Treatment Provide reduced
  treatment for the entire project based on T
• Allowable treatment reductions for specific BMPs
  (i.e. exfiltration trench), see LD Vol. 2,
  Section 1115.6.1 and 1115.6.2

17
Design Requirements

• Redevelopment No increase to runoff coefficient
• The area within existing ODOT R/W is considered
  impervious area for the purpose of
  post-construction BMP calculations

18
Design Requirements

• Redevelopment
• Projects that do not add impervious area outside
  the existing R/W are considered redevelopment
• Includes most ultra-urban projects and divided
  highways that widen toward the median

Widening toward the median would be considered
redevelopment for this divided highway
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Design Requirements

• What does Redevelopment mean for the amount of
  treatment required?
• Localized Treatment Provide 100 treatment for
  an area equal to 20 of the Project EDA
• or
• Project Wide Treatment Provide 20 treatment
  for the entire project
• Allowable treatment reductions for specific BMPs
  (i.e. exfiltration trench), see LD Vol. 2,
  Section 1115.6.1

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Design Requirements

• When storm water treatment is being applied using
  a Localized Treatment
• Credit toward meeting the treatment goal ( of
  EDA) is only applied to the portion of the
  contributing drainage area to the BMP within the
  roadway right-of-way (on-site).
• Any offsite contributing drainage area must be
  included in the BMP calculations for sizing
  purposes (i.e. width of ditch, length of ExT,
  etc.). The offsite area will not be included in
  the reduction of the required amount of project
  EDA that requires treatment.

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Redevelopment Vegetated Biofilter
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Redevelopment Vegetated Biofilter

• Design Examples for vegetated biofilters and
  exfiltration trenches can be found at the
  following website
• http//www.dot.state.oh.us/Divisions/ProdMgt/Produ
  ction/bmp/Pages/PostConstructionBMP.aspx

23
Design Requirements

• Water Quantity/Water Quality Differences
• Most linear BMPs treat water quality only
• Water quantity post-construction BMPs are
  typically detention facilities (difficult to fit
  in the linear transportation footprint)

24
Design Requirements

• Water Quantity (stream protection/stability)
  treatment not needed when
• One or less acre of new impervious area is
  created in new permanent right-of -way area being
  acquired for the project
• Discharging to 4th order stream
• Ultra-urban areas

25
Design Requirements

• Water Quantity alternative options
• Stream Protection based on culvert/bridge design
• Grade Controls for bridges and culverts
• LD Volume 2, Section 1115.2 provides additional
  information for culvert design options that
  provide water quantity credit (i.e. concrete
  aprons, bankfull design)

OEPA considers cutoff walls at culverts as a
grade control
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Design Requirements

• Nothing fits my project What now?
• ODOT-Let Projects Contact ODOT Central Office
  Production (Mike Wawszkiewicz)
• Local-Let Projects Contact Ohio EPA District
  Contact
• http//www.epa.state.oh.us/dsw/storm/contacts_stor
  m.html
• Possible Options at increased ratio (1.51 WQv)
• Offsite Mitigation
• Conservation Easements
• Offsite mitigation and conservation easements
  should be coordinated through Ohio EPA prior to
  NOI submittal

27
ODOT Experiences

• Consider the impacts of BMPs during plan
  development!
• Right-of-way Issues need to be identified early
• Take advantage of the treatment reductions
  allowed through the CGP and LD Volume 2.
• Take the time to calculate the T.
• Do not provide post-construction BMPs on Routine
  Maintenance Projects
• Why?
• Construction Cost
• R/W Cost and Acquisition Time
• Especially Vegetated Biofilters
• Maintenance Costs and Time to Maintain!!!!

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ODOT Experiences

• Design Considerations
• Depth of BMP (manufactured system)
• Location of BMP for access. Vacuum trucks needed
  for manufactured systems.
• Confined Space issues
• Can one manufactured system replace long runs of
  Exfiltration Trench? The initial cost may be
  higher. However, for maintenance purposes, it
  may be more beneficial to use a single
  manufactured system.

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ODOT Experiences

• Design Considerations (cont.)
• Detention Facilities Consider the effects of
  ponding water on the upstream drainage system.
• Culvert tailwater effects
• Ditch flow depths
• Storm sewer capacity

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ODOT Experiences

• Constructability Issues
• Utility Conflicts
• Maintaining BMPs free of construction debris
  (sequencing of construction activities)
• Condition of BMP at point of hand-off from
  construction to maintenance

31
ODOT Experiences

• Maintenance Issues
• Understand the materials/equipment/training
  needed for maintenance are available for the
  specified BMPs
• Disposal of BMP wastesHazardous?

32
Maintenance Responsibilities

• Part IV.B.1 of CGP requires that a maintenance
  agreement is in place when filing the NOT
• ODOT will maintain BMPs on ODOT maintained
  roadways and facilities

33
Maintenance Responsibilities

• Maintenance Issues
• Where are the BMPs? ODOT is developing an
  inventory of post-construction BMPs on ODOT
  roadways
• Training of ODOT staff (County Managers) on
  maintenance procedures
• OEPA can audit MS4s.

34
Maintenance Responsibilities

• Maintenance Issues
• Frequency for clean out of some linear BMPs is
  still unknown (i.e. Exfiltration Trench)
• Level of effort for some BMPs may be high based
  on frequency

35
Maintenance Responsibilities

• ODOT projects that extend onto Local Public
  Agency roadways
• Similar to other roadway features, ODOT will NOT
  maintain post-construction BMPs outside of ODOT
  right-of-way
• Local is responsible for maintenance
• Coordination during Preliminary Legislation
  development

36
Maintenance Responsibilities

• ODOT Projects extending onto LPA roadways
• Local may request a specific BMP type based on
  maintenance concerns
• ODOT may require Local to pay the difference in
  cost

37
Permitting Responsibilities

• Local-let LPA projects filed through ODOT
• Local agency files the NOI
• The LPA is responsible for providing
  post-construction BMP that meet Ohio EPA
  expectations (may use LD Volume 2 or other EPA
  approved guidance)
• The LPA, not ODOT, must coordinate with Ohio EPA
  if deficiencies are identified.

38
Whats next?

• Watershed Specific Permits
• Big Darby
• Portions of the Olentangy
• ODOT Research
• Exfiltration Trench - Performance, Durability and
  Maintenance
• Vegetated Biofilter - Performance
• Refinements to existing BMPs and continued
  monitoring

39
Watershed Specific Permits

• Big Darby
• Counties affected Logan, Champaign, Clark,
  Union, Madison, Franklin, Pickaway
• Effective Date October 27, 2006
• Riparian Setback and Groundwater Mitigation
• Sediment Pond size 134 CY/Ac of drainage
• Total Suspended Solids testing
• 45 mg/l TSS performance required

40
Watershed Specific Permits

• Olentangy
• Counties affected Morrow, Marion, Delaware,
  Franklin
• Issued January 23, 2009
• Effective Date April 8, 2009
• Riparian Setback Mitigation
• Sediment Pond size Same as Standard CGP

41
Watershed Specific Permits

• Ohio EPA Requirements
• Submittal of SWPPP with NOI application
• ODOT submits temporary sediment basin locations,
  post-construction BMP locations, and mitigation
  calculations. Contractor completes remainder of
  SWPPP when project is awarded.
• 45-day review period (standard CGP is 21 day
  review)

42
Watershed Specific Permits

• Mitigation for mitigation
• Overlapping Mitigation resulting from State or
  Federal environmental regulations (i.e. 404/401)
  may be adjusted in recognition of these
  requirements.

43
Watershed Specific Permits

• Redevelopment Projects covered by Watershed
  Specific Permits
• Projects located within the delineated setback
  boundary are exempt from Riparian Setback
  Mitigation provided the proposed project does not
  further intrude the delineated setback boundary.

44
Watershed Specific Permits

• Big Darby and Olentangy were generated by TMDL
  recommendations
• More TMDL watersheds have potential to become
  Watershed Specific Permits.

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Detention Basin
Exfiltration Trench
Vegetated Biofilter
Manufactured System
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Questions?

• Mike Wawszkiewicz, P.E.
• Phone [phone]
• Email michael.wawszkiewicz_at_dot.state.oh.us
• ODOT Post-Construction BMP Website
• http//www.dot.state.oh.us/Divisions/ProdMgt/Prod
  uction/bmp/Pages/PostConstructionBMP.aspx