Regulatory Requirements w w w. t r a n s p o r t a t i o n . o h i o . g o v 1
Overview Why Post-Construction BMPs? Overview of Post-Construction BMPs Overview of Regulations Construction General Permit ODOT’s Location and Design (L&D) Manual Volume 2 Alternative BMPs Off-Site Mitigation w w w. t r a n s p o r t a t i o n . o h i o . g o v 2
Overview Why Post-Construction BMPs? Overview of Post-Construction BMPs Overview of Regulations Construction General Permit ODOT’s Location and Design (L&D) Manual Volume 2 Alternative BMPs Off-Site Mitigation w w w. t r a n s p o r t a t i o n . o h i o . g o v 3
What are BMPs Supposed to Do? Post-Construction BMPs have Two Main Jobs: 1. Remove Pollutants – (Quality) 2. Reduce or Temporarily Hold Back Runoff from Stream – (Quantity) Quality: By Removing Sediment, Systems Remove Other Pollutants Quantity: Stream Stability – Limit Stream Erosion and Hydromodification from Higher Flow Rates and Higher Runoff Volumes w w w. t r a n s p o r t a t i o n . o h i o . g o v 4
Designing / Reviewing BMPs Is the BMP going to do a good job removing pollutants? Is the BMP going to help limit stream problems from increased flow rate and volume? w w w. t r a n s p o r t a t i o n . o h i o . g o v 5
Overview Why Post-Construction BMPs? Overview of Post-Construction BMPs Overview of Regulations Construction General Permit ODOT’s Location and Design (L&D) Manual Volume 2 Alternative BMPs Off-Site Mitigation w w w. t r a n s p o r t a t i o n . o h i o . g o v 6
BMPs: Many Different Names Source BMP Name Source BMP Name Manufactured System Wet Extended Detention Basin ODOT Quality Vegetated Biofilter Constructed Extended Detention Wetland Only Vegetated Filter Strip Dry Extended Detention Basin EPA CGP Table 4a Detention Basin Permeable Pavement – Extended Detention Retention Basin Underground Storage – Extended Detention ODOT Bioretention Cell Sand & Other Media Filtration – Extended Detention Quality and Infiltration Trench Bioretention Area/Cell Quantity Infiltration Basin Infiltration Basin EPA CGP Constructed Wetland Infiltration Trench Table 4b ODOT Underground Detention Permeable Pavement – Infiltration Quantity Stream Grade Control Underground Storage - Infiltration Only Grass Swales Grass Filter Strips Rain Barrels EPA CGP Alt. BMPs Green Roofs Catch Basin Inserts Hydrodynamic Separators w w w. t r a n s p o r t a t i o n . o h i o . g o v 7
BMPs: Only a Few Categories DETENTION INFILTRATION FLOW THROUGH BMPS BIORETENTION w w w. t r a n s p o r t a t i o n . o h i o . g o v 8
BMPs: Main Treatment Mechanism Detention Rely on hydraulic residence time to allow sediment to settle out (sedimentation) Infiltration Rely on soil infiltration capacity Bioretention Rely on physical filtering through planting media Filtering occurs slowly Flow Through BMPs Rely on physical filtering or hydrodynamic separation Filtering occurs quickly w w w. t r a n s p o r t a t i o n . o h i o . g o v 9
Looking at BMPs Simply Four Categories Detention Infiltration Bioretention Flow Through BMPs Two Jobs Pollutant Removal (Quality) Stream Protection from Erosion (Quantity) w w w. t r a n s p o r t a t i o n . o h i o . g o v 10
BMPs: Quality vs. Quantity Source BMP Name Category Quality Quantity Manufactured System Flow Through X ODOT Quality Vegetated Biofilter Flow Through X Only Vegetated Filter Strip Flow Through X Detention Basin Detention X X Retention Basin Detention X X ODOT Bioretention Cell Bioretention X X Quality and Infiltration Trench Infiltration X X Quantity Infiltration Basin Infiltration X X Constructed Wetland Detention X X ODOT Underground Detention Detention X Quantity Stream Grade Control (Other) X Only w w w. t r a n s p o r t a t i o n . o h i o . g o v 11
Audience Participation! w w w. t r a n s p o r t a t i o n . o h i o . g o v 12
Audience Participation (1 of 9) Category Detention Basin Detention Infiltration Bioretention Flow Through Performance Quality Quantity w w w. t r a n s p o r t a t i o n . o h i o . g o v 13
Audience Participation (1 of 9) Category Detention Basin Detention X Infiltration Bioretention Flow Through Performance Quality X Quantity X w w w. t r a n s p o r t a t i o n . o h i o . g o v 14
Audience Participation (2 of 9) Category Infiltration Trench Detention Infiltration Bioretention Flow Through Performance Quality Quantity w w w. t r a n s p o r t a t i o n . o h i o . g o v 15
Audience Participation (2 of 9) Category Infiltration Trench Detention Infiltration X Bioretention Flow Through Performance Quality X Quantity X w w w. t r a n s p o r t a t i o n . o h i o . g o v 16
Audience Participation (3 of 9) Category Bioretention Detention Infiltration Bioretention Flow Through Performance Quality Quantity w w w. t r a n s p o r t a t i o n . o h i o . g o v 17
Audience Participation (3 of 9) Category Bioretention Detention Infiltration Bioretention X Flow Through Performance Quality X Quantity X w w w. t r a n s p o r t a t i o n . o h i o . g o v 18
Audience Participation (4 of 9) Category Hydrodynamic Separator Detention Infiltration Bioretention Flow Through Performance Quality Quantity w w w. t r a n s p o r t a t i o n . o h i o . g o v 19 Image: 3P Technik UK
Audience Participation (4 of 9) Category Hydrodynamic Separator Detention Infiltration Bioretention Flow Through X Performance Quality X Quantity w w w. t r a n s p o r t a t i o n . o h i o . g o v 20 Image: 3P Technik UK
Audience Participation (5 of 9) Category Filter Strip Detention Infiltration Bioretention Flow Through Performance Quality Quantity w w w. t r a n s p o r t a t i o n . o h i o . g o v 21
Audience Participation (5 of 9) Category Filter Strip Detention Infiltration Bioretention Flow Through X Performance Quality X Quantity w w w. t r a n s p o r t a t i o n . o h i o . g o v 22
Audience Participation (6 of 9) Category Vegetated Biofilter Detention Infiltration Bioretention Flow Through Performance Quality Quantity w w w. t r a n s p o r t a t i o n . o h i o . g o v 23
Audience Participation (6 of 9) Category Vegetated Biofilter Detention Infiltration Bioretention Flow Through X Performance Quality X Quantity w w w. t r a n s p o r t a t i o n . o h i o . g o v 24
Audience Participation (6 of 9) Category Retention Basin Detention Infiltration Bioretention Flow Through Performance Quality Quantity w w w. t r a n s p o r t a t i o n . o h i o . g o v 25
Audience Participation (6 of 9) Category Retention Basin Detention X Infiltration Bioretention Flow Through Performance Quality X Quantity X w w w. t r a n s p o r t a t i o n . o h i o . g o v 26
Audience Participation (7 of 9) Category Pervious Pavement Detention Infiltration Bioretention Flow Through Performance Quality Quantity w w w. t r a n s p o r t a t i o n . o h i o . g o v 27
Audience Participation (7 of 9) Category Pervious Pavement Detention ? Infiltration ? Bioretention Flow Through Performance Quality X Quantity X w w w. t r a n s p o r t a t i o n . o h i o . g o v 28
Audience Participation (8 of 9) Category Underground Detention Detention Infiltration Bioretention Flow Through Performance Quality Quantity w w w. t r a n s p o r t a t i o n . o h i o . g o v 29
Audience Participation (8 of 9) Category Underground Detention Detention X Infiltration Bioretention Flow Through ? Performance Quality ? Quantity X w w w. t r a n s p o r t a t i o n . o h i o . g o v 30
Audience Participation (9 of 9) Category Detention Basin with Detention Lined Channel Infiltration Bioretention Flow Through Performance Quality Quantity w w w. t r a n s p o r t a t i o n . o h i o . g o v 31
Audience Participation (9 of 9) Category Detention Basin with Detention Lined Channel Infiltration Bioretention Flow Through Performance Quality Quantity NONE Det. Basin for Flooding; not WQ V Treatment w w w. t r a n s p o r t a t i o n . o h i o . g o v 32
Overview Why Post-Construction BMPs? Overview of Post-Construction BMPs Overview of Regulations Construction General Permit ODOT’s Location and Design (L&D) Manual Volume 2 Alternative BMPs Off-Site Mitigation w w w. t r a n s p o r t a t i o n . o h i o . g o v 33
Overview of Regulations w w w. t r a n s p o r t a t i o n . o h i o . g o v 34
Construction General Permit vs. ODOT’s L&D Vol. 2 Ohio EPA Construction General Permit: Any land disturbance over 1 ac. must meet requirements in NPDES permit CGP: Roadway projects by public entities can use ODOT’s L&D, Vol. 2 as an alternate to post-construction BMP requirements L&D post-construction BMP guidance reviewed by Ohio EPA w w w. t r a n s p o r t a t i o n . o h i o . g o v 35
CGP vs. L&D Vol. 2 Ohio EPA Construction General Permit: 1 – 2 ac.: Small construction, may use alternative BMP if meet certain conditions >= 2 ac.: Construction, prescriptive requirements (Table 4a and 4b BMPs) ODOT L&D. Volume 2 Different requirements… w w w. t r a n s p o r t a t i o n . o h i o . g o v 36
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