11/2/2018 Lacy Road: Meeting Storm Water Treatment and Infiltration Requirements within an Urban Right-of-Way APWA Wisconsin Fall Conference Session 2C November, 2018 Anne Anderson, PE Rick Eilertson, PE Mead & Hunt, Inc. AECOM , formerly City of Fitchburg 2C: Meeting Storm Water Treatment and Infiltration Requirements within an Urban Right-of-Way Learning Objectives : 1. Evaluate opportunities for meeting storm water treatment and infiltration requirements within an urban right-of- way. 2. Identify obstacles that may be encountered when attempting to incorporate storm water treatment and infiltration practices within and urban right-of-way. 3. Describe lessons learned for stormwater treatment and infiltration requirements within an urban right-of- way. Please rate this session in Whova 1
11/2/2018 Lacy Road Agenda • Project Background • Obstacles/Challenges • Stormwater Options • BMP Maintenance • Lessons Learned Existing Conditions • Lacy Road was a 2- lane rural roadway with 3' paved shoulders • Major Collector, traverses the entire east-west length of the City (6 miles) • Many residential properties and many community destinations 2
11/2/2018 Project Costs • In 2014, the Lacy Road project was awarded funding from the MPO • Grant to cover 50% of construction costs • Maximum grant contribution: $2,540,000 • Total stormwater cost: $520,000 • Total project cost: $5M Project Goals Rural Urban Minimize right ‐ of ‐ way acquisition Provide pedestrian and bicycle accommodations Improve safety Enhance driveway access and improve sight distance Speed Limit compliance Reconstruct facilitate drainage Utilize sustainable stormwater management techniques 3
11/2/2018 Stormwater Goals City of Fitchburg Street Construction 40% TSS reduction New Construction NEW IMPERVIOUS Maintain pre ‐ development runoff rates Remove 80% TSS Infiltrate 90% WisDOT Stormwater Treatment Goals Summary 40% TSS reduction, rural to urban Cost Effective Stormwater Challenges • Limited Right ‐ of ‐ Way • Existing topography • Municipal & private well locations • Number of drainage outfalls • Presence of rock 4
11/2/2018 Limited Right-of-Way Right ‐ of ‐ way width varies from 66’ to 90’ Existing Lacy Road is not centered in right ‐ of ‐ way Existing Topography Grades fall quickly to the north Steep driveways on the north Challenging to widen road footprint 5
11/2/2018 Municipal and Private Well Locations 3 Drainage Area Outfalls • Insert drainage area map Fish Hatchery Road Central West East Syene Road 6
11/2/2018 Central Drainage Area Outfall 13 Locations of Rock 7
11/2/2018 Potential Stormwater Components • Ponds • Bioswales • Permeable street pavers • Porous path Stormwater Options • Bioswales Option • Porous Bike Lane Option 8
11/2/2018 Bioswale Option OFF SITE TREATMENT Bioswale Widths 2’ 6’ • North side 22 feet minimum • South side 14 feet minimum 9
11/2/2018 Potential Pond Porous Bike Lane 10
11/2/2018 Comparing Options Bioswales Porous Bike Lane Option - Bioswales and Ponds: $2,730,000 Option - Porous Pavement: $2,072,000 Option B and P costs include basic road & storm sewer costs for ease of comparison Selected Typical Section on Lacy Road 10’ travel lanes (11’) 5’ sidewalk 4’ buffered bike lanes (2’ 7’ terrace buffer) 24 ‐ inch curb and gutter (30”) 8’ ‐ 10’ shared use path 11
11/2/2018 Stormwater Alternatives • Ponds • Bioswales • Permeable street pavers • Porous path or… • Pervious Pipe & Infiltration Trench Pervious Pipe & Infiltration Trench 12
11/2/2018 Selected Stormwater Treatment Main Treatment • Pervious Pipe & Infiltration Trenches • Porous asphalt path Pre ‐ Treatment • Inlet filters and, 3 foot sumps and back ‐ pitched pipes Stormwater Modeling • Started with HydroCAD for existing development • In order to analyze peak flows, the sections of storm sewer with perforations were modeled in Storm and Sanitary Analysis (SSA) 13
11/2/2018 Stormwater Modeling 48% TSS 165% 14
11/2/2018 Infiltration Trench Trench Depth Trench Area Infiltration Outfall SLAMM CONTROL Trench Width (ft) (sf) Rate (in/hr) infiltration trench modeled as 3.5 feet, 1 foot West biofiltration 10 below pipe 5,720 0.500 infiltration trench modeled as 4 feet total, 1 Central biofiltration 14 foot below pipe 22,115 0.500 trench modeled as biofiltration and 4 feet total, 1 East porous path 10 foot below pipe 10,740 0.500 Cost Comparisons Option Construction Cost Maintenance Cost Bioswales and $2.7 M $ Ponds Permeable Street & $2.1M $$$ Ponds Infiltration Trenches $2.1M $ & Porous Pipe 15
11/2/2018 Pervious Pipe Infiltration Trench Locations of Infiltration Trenches 16
11/2/2018 Locations of Infiltration Trenches Locations of Infiltration Trenches • Add a plan sheet showing location of trenches… 17
11/2/2018 Stormwater Infiltration Trenches 18
11/2/2018 Storm Sewer Installation Pre-Treatment • Inlet Filters • Back-pitched pipes 19
11/2/2018 Permanent Inlet Filter Bags Oil absorbent pouches clip into filter bag Location of porous asphalt path 20
11/2/2018 Porous asphalt path Porous Asphalt Path Ayres Associates image 21
11/2/2018 Porous Asphalt Path BMP Maintenance, Storm System • Inspect the system annually and after large rain events • Inspect structures annually for sediment buildup • Remove sediment with vacuum pump when > 6 inches • Street sweep a minimum of 2 x / year • Inspect inlet filters 2 x / year • Replace oil absorbent pouches 22
11/2/2018 BMP Maintenance, Porous Asphalt Path • Use broom or rubber blade on plow for snow removal to minimize scraping • Vacuum sweep the porous pavement two times per year Lessons Learned – Stone Bedding • Open graded stone: WisDOT specifications, use a Special item for stone so you get washed stone instead of open-graded base aggregate (OGBA) 23
11/2/2018 Lessons Learned – Pipe • Concrete collar specified, but special couplers are now available • Shallow plastic pipe requires special care by contractor and subcontractors to minimize damage 47 Lessons Learned – Trench Transitions • Consider transitions to solid pipe and less pervious bedding when you want to minimize flow horizontally along the trench bedding 24
11/2/2018 Lessons Learned • Modeling: non-conventional design may require flexible software • Inlets: weir overflow wall off-center 25
11/2/2018 51 Lacy Road: Meeting Storm Water Treatment and Infiltration Requirements within an Urban Right-of-Way Thank You APWA Wisconsin Fall Conference Session 2C November, 2018 Anne Anderson, PE Rick Eilertson, PE Mead & Hunt, Inc. AECOM , formerly City of Fitchburg 26
11/2/2018 2C: Meeting Storm Water Treatment and Infiltration Requirements within an Urban Right-of-Way Learning Objectives : 1. Evaluate opportunities for meeting storm water treatment and infiltration requirements within an urban right-of- way. 2. Identify obstacles that may be encountered when attempting to incorporate storm water treatment and infiltration practices within and urban right-of-way. 3. Describe lessons learned for stormwater treatment and infiltration requirements within an urban right-of- way. Please rate this session in Whova 27
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