1. Construction Perspectives: Non-vegetated GI and Effective Engineer-Contractor Communication Construction Perspectives: Non-vegetated GI and Effective Engineer-Contractor Communication Presented to: CWEA Stormwater Conference Spring 2015 Seminar Presented to: CWEA Stormwater Conference Spring 2015 Seminar Presented by: April 17, 2015 Zack Knight, PE

2. 2 Presentation Outline Purpose, Goals, and Context Case Studies: Plans and Specs vs. the Constructed Project Infiltration beds and trenches Porous (permeable) pavement: asphalt and pavers Street structures and streetscaping Stormwater structure filters, flow devices, and modifications Parting Tips for Engineer-GI Contractor Communication Avoiding miscommunication Work in challenging environments “Newbie” contractors and their subcontractors/suppliers

3. 3 Purpose and Goals Purpose: To share construction lessons-learned and explore the evolving nature of green infrastructure design. Show projects up to 5 years old Illustrate spot design areas requiring attention Design/construction challenges and solutions Share parting tips on effective contractor communication

4. 4 Context.. and reflection The road less traveled: CNY There are 2 Seasons: Winter…

5. 5 And Construction!

6. 6 “Save the Rain” Program Highlights Onondaga County, NY 7,660 acres 6.1 Billion Gallons Total Annual Combined Sewage in Sewer Service Area 170+ Projects Completed to Date, 100,000,000 gallons of capture

7. 7 Project Completed in 2012 Runoff Reduction = 866,000 gallons annually Construction Cost = $986,000 Planters, Curb Extensions, and Porous Pavers Challenges: Service Utilities Paver Layout Case Study #1: Streetscape on Water Street

8. 8 Case Study #1: Water Street Green Gateway

9. 9 Case Study #1: Water Street Green Gateway Utility Solutions: -Wrap Utilities in trench -Shift GI (if possible) -Enhanced survey (when possible)

10. 10 Case Study #1: Water Street Green Gateway Paver Layout Solutions: -Mockups -Addressing Curb Irregularities before Installation

11. 11 Paver Layout Solutions: -Detailed paver specifications, details, and qualifications

12. 12 Case Study #2: Porous Asphalt - ROW Parking Lane Project Completed in 2011 Demonstration project for a 4’ wide porous asphalt strip in public residential ROW (widening) Construction Cost = $66,000 Challenges: Specifications vs. Supply Placement

13. 13 Case Study #2: Porous Asphalt - ROW Parking Lane

14. 14 Case Study #2: Porous Asphalt - ROW Parking Lane Specification Solutions: -NAPA, FHWA, or Institutional -Integrate with permeable State mixes -Pavement design; consider geogrids Supply Solutions: -Work with Batch Plant ASAP -Binder, fibers, other admixtures to match climate and specified testing requirements

15. 15 Case Study #2: Porous Asphalt - ROW Parking Lane Placement Solutions (the quick notes): -Contractor/Paver Pre-Pave Meeting -Ideally track paver w/ smaller roller (8- to 10-ton). 1-2 passes – it’s porous! -Haul time/distance, ambient temp (55 F), mix temp (varies, 275-325 F), and surface protection critical.

16. 16 Case Study #3: City Parking Lot #4 Runoff Reduction = 2,474,000 gallons annually Construction Cost = $607,000 Porous asphalt w/ subsurface infiltration bed Challenges: Longitudinal slope Subsurface Soils

17. 17 Case Study #3: City Parking Lot #4 Sloped finished grade Solution: -Stepped bed, keeping connectivity using control structures

18. 18 Case Study #3: City Parking Lot #4 Poor subgrade soils solution: -Create a slow release system

19. 19 Case Study #3: City Parking Lot #4 - Slow release using PVC weirs and orifices - Stainless, pre-eng/fab, and hydraulic brake options

20. 20 Case Study #3: City Parking Lot #4

21. 21 Case Studies #4-5: Leavenworth Park and Geddes St. Leavenworth 2,474,000 gal RR Cost = $607,000 Curbside bioswale Geddes 543,000 gal RR Cost = $279,000 Curbside bioswale Common Challenge: Curbing

22. 22 Case Studies #4-5: Leavenworth Park and Geddes St. Leavenworth 2,474,000 gal RR Cost = $607,000 Curbside bioswale Geddes 543,000 gal RR Cost = $279,000 Curbside bioswale Common Challenge: Curbing

23. 23 Case Studies #4-5: Leavenworth Park and Geddes St. Leavenworth: Curbside Parking Curbing Solutions: -Utilize a carriage walk -Different options for carriage walk at curb cuts

24. 24 Case Studies #4-5: Leavenworth Park and Geddes St. Leavenworth

25. 25 Case Studies #4-5: Leavenworth Park and Geddes St. Geddes St. Traffic Hazards

26. 26 Case Studies #4-5: Leavenworth Park and Geddes St. Geddes St. Solutions: -Careful use of standard details -Reinforcement adjacent to GI

27. 27 Summary of Solutions to Challenges ChallengesSolutions Service UtilitiesWrapping, Shift GI, Enhanced survey Porous Paver InstallationMock-Ups, Detailed specs Porous Asphalt Specification Tested resources, integrate with State mixes, pavement design-consider geogrids Porous Asphalt SupplyBatch plant coordination, mix design Porous Asphalt PlacementPre-pave meeting, proper equipment/logistics Infiltration Bed Slope/SubgradeStepped bed, control structures, slow release GI Curbing-ParkingCarriage walk, curb cut details GI Curbing-TrafficReinforced section

28. 28 Parting Words – Contractor Communication The most important part of ensuring a quality constructed project is effective communication with the contractor. As the A/E, we are there to know and enforce the contract fairly and firmly Miscommunication to avoid as A/E’s Email and paper when phone or site visit (in person) is the right thing to do Speculation or expressing opinion Keep records FAT (factual, accurate, and timely) – saving for record or an appropriate use

29. 29 Parting Words – Contractor Communication Green infrastructure is often located in challenging environments Contractor site security, work hours, schedule/sequencing Work with owner, in detail, to coordinate down time or disruption Progress meetings with Owner and organizational resources

30. 30 Parting Words – Contractor Communication Working with new green infrastructure contractors Pre-qualification based on type of GI Preconstruction meeting(s) – as many parties as possible Supplier, vendor, and continuous progress meetings Subcontractors Often avoided because contract is with prime Meet with the pavers, landscapers, and tradesman Meet with the suppliers and their “QA-QC” personnel

31. 31 THANK YOU! Questions?