1. Innovative Use of Porous Pavement for Treatment of Roadway Runoff Everett Gupton, PE Ron Horres, PE ASCE-EWRG & APWA Sustainable Stormwater Symposium September 15, 2010

2. Innovative Use of Porous Pavement for Treatment of Roadway Runoff WSDOT “Ecology Mix” Background Pioneer Parkway – The Next Step U.S. Highway 199 – Dowell Road to RCC – Project Description – Multi-Use Pathway Design for Stormwater Treatment – Future – Sampling and Testing Acknowledgements and More Information

3. Innovative use of Porous Pavement OR Innovative use of Ecology Mix Treatment System OR Utilize Both to Meet Project goals

4. WSDOT Ecology Embankment Goal to provide Stormwater BMP for use in areas with limited ROW availability Provide highway runoff with – Basic Treatment - Suspended Solids – Phosphorus Treatment – Enhanced Treatment – Dissolved Metals – Oils Treatment Treatment provide via filtration, chemical precipitation, sorption and biological uptake

5. WSDOT Ecology Embankment Crushed Rock Dolomite Gypsum Perlite

6. WSDOT Ecology Embankment – Typical Section

7. WSDOT Ecology Embankment – Effectiveness Suspended Solids – Goal of > of 80% removal or 20 mg/l met Phosphorus – averaged > 80% removal Zinc – median removal of 78.7 % Copper – median removal of 39.2 % Oil – not tested, removal meet goals based on inferred removal mechanisms

8. Pioneer Parkway BRT Project Bus Rapid Transit system for Lane County Transit in the City of Springfield, OR 1.8 miles of new busway and associated stations Limited space availability for stormwater treatment Confined impervious surface at dedicated busway

9. Pioneer Parkway – Busway Ecology Embankment Filter Strip

10. Pioneer Parkway - Construction Busway construction showing: Polyethylene Sheeting Perforated Drain Pipe Water Quality Filter Material

11. Pioneer Parkway - Construction Completed busway with Ecology Embankment Filter Strip Seeding of strip beginning to emerge

12. US Highway 199 Widening Project Summary Widening of US Highway 199 (US 199) in Grants Pass Construction of new and extended bike/pedestrian path Project Constraints Limited ROW/Property Acquisition Expenses DEQ and SLOPES IV Stormwater Regulations Low Infiltrative Soils

13. Governing Stormwater Regulations From ODOT Bulletin GE09-02(B) – Stormwater runoff from a project shall not cause violations of water quality standards in the receiving water – Provide water quality treatment for the total Contributing Impervious Area using the most effect techniques practicable for the site – Avoid an increase in pre vs. post-construction flows from 42% of 2-year event to 10-year event. Oregon DEQ – Treat pollutants of concern in roadway runoff (Petroleum, PAHs, Sediment, & Metals) SLOPES IV – All CIA runoff must be treated prior to commingling with offsite water.

14. Selection of Treatment BMPs Areas with No Pathway – Biofiltration Swale Areas with Pathway – Pervious Pavement with Infiltrative Trench

15. Plan View of Pervious Pavement Trench System 1 1.Porous Asphalt Pavement Walking/Bike Path 2.Perforated Underdrain Collection Pipe 3.Existing Stormwater Crossing Culvert 4.New Manhole Connection to Existing Stormwater Culvert 5.New Pipe Connection to Existing Ditch/Stream at Grading Limits 6.Cleanouts for Maintenance 2 3 4 4 5 5 6 R/W

16. Profile View of Pervious Pavement Trench System 3 1.Existing Ground Surface Profile 2.Proposed Ground Surface Profile 3.8” Perforated HDPE or PVC Underdrain Collection Pipe 4.Cleanout for Maintenance of Perforated Pipe 5.New Manhole Connection to Existing Stormwater Culvert 3 4 5 12

17. Pervious Pavement with Infiltrative Trench 1 8 3 5 1.Pervious HMAC wearing course – 3” thickness 2.Porous choke aggregate – 1” thickness 3.Porous graded aggregate base – 10” thickness under pathway 4.Drainage geotextile (pervious) 5.Ecology Mix – 18” thickness 6.Granular drain backfill material – 1’ – 2’ thickness 7.Perforated HDPE or PVC drainpipe 8.1’ wide mountable curb 9.Subgrade geotextile (impervious) 2 6 9 9 9 4 7 11’5’ 4

18. Pervious Pavement with Infiltrative Trench 2 1.Aggregate shoulder collects first flush preventing sediment transport onto pervious pavement, minimizing clogging and the amount of maintenance needed. 2.Porous Aggregate provides volume for detention storage (sized for 25- Year). 3.Ecology Mix provides environment for treatment and slows runoff for detention. 4.Perforated drainpipe allows from connection to existing storm system after treatment occurs. 5.Outlet for events larger than the 25-Year storm. Water will exit to the backside ditch and eventually to the cross culvert. 3 1 4 5

19. Trench System Hydraulics Maximum flow rate through the trench system is dependent on the surface area of the Ecology Mix (L*W) along with the infiltration rate (q) Q = L * W * q Using SCS Type 1A storm, a volume balance was developed to track flow into and out of the system. (Qin – Qout) * ∆t = Volume of Storage Storage Volume detained in the aggregate base is slowly discharged at the tail end of the storm. The maximum volume at any time step was compared to the volume of the void spaces in the aggregate base to ensure containment of 25-Year Storm.

20. Water Quality Storm Hydrograph Storage In Aggregate & Ecology Mix Treatment Time Stored Volume Discharge Per SLOPES IV: WQ Storm is defined as 50% of the cumulative rainfall from the 2-Year, 24-hour Storm. Attributes Delayed Peak Small Reduction in Peak Flows Treatment Time is clearly visible

21. 10-Year Storm Hydrograph Storage In Aggregate & Ecology Mix Stored Volume Discharge Attributes Delayed Peak Flattened and Reduced Peak Discharge Greater Volume of Storage Flat Discharge Peak Flow

22. Hwy 199 – Future Plans Develop Sampling/Testing Plan to confirm treatment effectiveness Obtain funding source for Testing Project Phase 1 testing to obtain pre-development condition Phase 2 of testing to measure effectiveness of installed system

23. Acknowledgements ODOT Region 3 – Hwy 199, Dowell to RCC Project Staff Lane County Transit / City of Springfield / Pioneer Parkway Project Staff WSDOT Ecology Embankment – Technology Evaluation and Engineering Report, Herrera Environmental Consultants, Inc. July 14, 2006

24. Further Information Contact Everett Gupton or Ron Horres 503-274-8772 or Gupton@pbworld.com Horres@pbworld.com

25. Questions ?