1. MARCH 4, 2009 32 ND ANNUAL AIRPORT CONFERENCE HERSHEY, PA Innovative Approaches for Managing Stormwater Runoff: Constructed Wetlands

2. KIM MINKEL, NFTA Project Background

3. Buffalo Niagara International Airport 110 daily flights, 25 gates 96” Avg. snow fall ~330,000 gallons glycol 1.2 MGD stormwater runoff

4. Deicing operations and practices  Deicing at the gates.  Storm sewer design.  Parallel system routes storm and glycol water.  Glycol storage before discharging to a POTW.  Glycol capture by GRV’s 45-48%.

5. Environmental Concerns  1994 - SPDES permit  30 mg/L BOD5 and 500 mg/L glycol limit  Frequent permit exceeded  1995 - Vacuum sweeping  3/1998 - The Citizen Alliance Group targets NYSDEC  4/1998 NYSDEC issues Order on Consent - Comply by 2/99

6. Over the next 4 years… ~$13.1 million spent  deicing controls,  storage and  treatment Permit limits still exceeded Neighbor complaints Town prohibits discharge

7. Concerns Point source limit applying to a non-point source operation – Permit modification It’s not working –treat everything or reduce use? Large volumes – how do you treat this cost effectively? How do you pay for this?

8. Action Items  Open SPDES permit  2004 – Generic RFP issued  Petition for funding  Modify permit – stream impact  Treatment Alternatives (non-point source)  Eliminate (reduce) glycol

9. Alternatives considered Dedicated sewer line to POTW Anaerobic/aerobic onsite treatment Membrane bioreactors Recycling Infratek systems Reed bed subsurface wetland Centralized deicing recycling

10. Subsurface engineered wetland Advantage –  Lowest 20 year combined capital and operating cost  Effective treatment for stormwater  Totally Green process Disadvantage –  Space constraints  Public acceptance (Will it work?)

11. Go for it!  2005 - RFP for a Treatability Study and Conceptual design  2006 - Awarded to Jacques Whitford/NAWE/Urban  Treatability study showing >95% reduction in BOD  2007- Design phase completed

12. GARRET A. MEAL, P.E., URBAN ENGINEERING Stormwater Management Impacts

13. URBAN ENGINEERS Buffalo Engineering firm with 10 offices 475 staff along the East Coast Extensive airport and civil transportation experience NY and local environmental permitting experience

15. Existing Infrastructure  Storm System  Extensive Storm Network  Stormwater Vault (3+ MG)  Outfall  Glycol Containment  Major pipes  Glycol storage tanks  Snow melt pad  Sanitary sewer pump station

17. Objectives  Treat Glycol Concentrate  Treat Glycol Contaminated Storm  Maintain Runoff Control  Reduce or Control Deicing costs

18. What needs to be treated?  Concentrate – 100%  Simple  Common Pumped Discharge to sanitary  Replace pumps, discharge to WTS

19. What needs to be treated?  Storm  Would require 15 Million Gallons storage for 10 yr storm  25 Million Gallons for 100 yr storm  First Flush

20. Stormwater Management  Existing Design – Detention  Design Storm  Proposed Design for WTS Influent

21. Design Storm

22. First Flush Collection

23. Stormwater Management Strategies  Divert upstream areas directly to wetlands, where possible  Utilize wetlands for storm detention  Utilize glycol infrastructure year round  Design additional pumping capacity  Evaluate emergency overflows  Surface storage of severe storms

26. Conclusions  Storm Water Management Plan  Know what you are handling  How will you capture and hold water for treatment  Evaluate Resources – Can primary use be modified

27. SCOTT WALLACE, JW NAWE Glycol Treatment

28. Treatment Objectives Provide treatment of contained deicing fluid Design system for integration into airfield Integrate system into existing stormwater management

29. Why Wetlands? Subsurface flow constructed wetlands do not pose a bird-aircraft strike hazard (BASH) More stable than mechanical treatment systems Biggest challenge is oxygen transfer into subsurface flow beds!

30. Engineered Wetlands

31. Designed for Treatment

32. Drain Line Air Line Mulch Layer Influent Line Subsurface Bed Cross Section Water Level

33. Glycol Treatment Glycols are readily degradable by bacteria

34. Managing Peak Events

35. Process Sizing and Layout Cells are designed for a total load of 10,000 pounds of oxygen demand per day The equivalent to 50,000 people

36. Construction

53. Conclusions System operation scales to glycol usage In this case, the design had to handle variable flows and concentrations from at gate deicing The design provides flexible operations  Winter = glycol treatment  Summer = storm storage

54. Lessons Learned Communicate early and often Never forget your key mission Every airport is different Design with flexibility in mind Listen to your stormwater engineer