1. © 2015 EarthCon Consultants, Inc. All rights reserved. This material may not be reproduced, displayed, modified or distributed without the express prior written permission of the copyright holder. www.earthcon.com REMEDIAL APPROACH DESIGNED WITH POTENTIAL ADVERSE WEATHER CONDITIONS IN MIND: A CASE STUDY OF AN IMPACTED CREEK

2. © 2015 EarthCon Consultants, Inc. All rights reserved. This material may not be reproduced, displayed, modified or distributed without the express prior written permission of the copyright holder. Environmental Challenges BUSINESS SOLUTIONS ® www.earthcon.com Former Wood Treatment Facility Wilkinson and Amite Counties, Mississippi, near the town of Crosby, adjacent to Foster Creek

3. © 2015 EarthCon Consultants, Inc. All rights reserved. This material may not be reproduced, displayed, modified or distributed without the express prior written permission of the copyright holder. Environmental Challenges BUSINESS SOLUTIONS ® www.earthcon.com Site Location

4. © 2015 EarthCon Consultants, Inc. All rights reserved. This material may not be reproduced, displayed, modified or distributed without the express prior written permission of the copyright holder. Environmental Challenges BUSINESS SOLUTIONS ® www.earthcon.com Foster Creek A major tributary to the Homochito River - Mississippi River Drainage Basin In the Southern Rolling Plains of the Mississippi Valley Loess Plains ecoregion Flows through the Homochito National Forest

5. © 2015 EarthCon Consultants, Inc. All rights reserved. This material may not be reproduced, displayed, modified or distributed without the express prior written permission of the copyright holder. Environmental Challenges BUSINESS SOLUTIONS ® www.earthcon.com Foster Creek – 2004 Stream morphology can change quickly and dramatically due to rapid changes in stream flow during and after large storm events Very dynamic

6. © 2015 EarthCon Consultants, Inc. All rights reserved. This material may not be reproduced, displayed, modified or distributed without the express prior written permission of the copyright holder. Environmental Challenges BUSINESS SOLUTIONS ® www.earthcon.com 1971 1987-1989: recovery wells installed GWTS constructed 1986: Beginning of corrective action Wood treating operations end 198719961934 Wood treating operations begin 1985 Presence of creosote observed in Foster Cr 1986 Site Timeline

7. © 2015 EarthCon Consultants, Inc. All rights reserved. This material may not be reproduced, displayed, modified or distributed without the express prior written permission of the copyright holder. Environmental Challenges BUSINESS SOLUTIONS ® www.earthcon.com Distribution of NAPL (ca 1990) N

8. © 2015 EarthCon Consultants, Inc. All rights reserved. This material may not be reproduced, displayed, modified or distributed without the express prior written permission of the copyright holder. Environmental Challenges BUSINESS SOLUTIONS ® www.earthcon.com Remediation System

9. © 2015 EarthCon Consultants, Inc. All rights reserved. This material may not be reproduced, displayed, modified or distributed without the express prior written permission of the copyright holder. Environmental Challenges BUSINESS SOLUTIONS ® www.earthcon.com Spray Fields

10. © 2015 EarthCon Consultants, Inc. All rights reserved. This material may not be reproduced, displayed, modified or distributed without the express prior written permission of the copyright holder. Environmental Challenges BUSINESS SOLUTIONS ® www.earthcon.com Site Timeline Feb: USACE NWP No. 38 Nov: Begin remediating ~1,380’ section of Cr. Dec 11: heavy rains damage inflatable dam Nov: mtg with MDEQ Finalize remedy June: creosote globules obv in Foster Cr Nov: Topo map of Foster Cr developed Dec: Cr assessment 20082010 2011 Mar: 7” rain in 24-hrs Apr: 1 st bag wall installed June: 2 nd bag wall installed Dec: 5” rain in 48-hrs 2013 Jan: storm event, higher stream flows than Dec 2011 event June: enhanced Bag Wall 2, install gabion baskets 2014 Feb/Mar: 2 heavy rainfall events resulted in 200-yr flood event 2006

11. © 2015 EarthCon Consultants, Inc. All rights reserved. This material may not be reproduced, displayed, modified or distributed without the express prior written permission of the copyright holder. Environmental Challenges BUSINESS SOLUTIONS ® www.earthcon.com Foster Creek

12. © 2015 EarthCon Consultants, Inc. All rights reserved. This material may not be reproduced, displayed, modified or distributed without the express prior written permission of the copyright holder. Environmental Challenges BUSINESS SOLUTIONS ® www.earthcon.com Foster Creek

13. © 2015 EarthCon Consultants, Inc. All rights reserved. This material may not be reproduced, displayed, modified or distributed without the express prior written permission of the copyright holder. Environmental Challenges BUSINESS SOLUTIONS ® www.earthcon.com Creek Assessment

14. © 2015 EarthCon Consultants, Inc. All rights reserved. This material may not be reproduced, displayed, modified or distributed without the express prior written permission of the copyright holder. Environmental Challenges BUSINESS SOLUTIONS ® www.earthcon.com Site Timeline Feb: USACE NWP No. 38 Nov: Begin remediating ~1,380’ section of Cr. Dec 11: heavy rains damage inflatable dam Nov: mtg with MDEQ Finalize remedy June: creosote globules obv in Foster Cr Nov: Topo map of Foster Cr developed Dec: Cr assessment 20082010 2011 Mar: 7” rain in 24-hrs Apr: 1 st bag wall installed June: 2 nd bag wall installed Dec: 5” rain in 48-hrs 2013 Jan: storm event, higher stream flows than Dec 2011 event June: enhanced Bag Wall 2, install gabion baskets 2014 Feb/Mar: 2 heavy rainfall events resulted in 200-yr flood event 2006

15. © 2015 EarthCon Consultants, Inc. All rights reserved. This material may not be reproduced, displayed, modified or distributed without the express prior written permission of the copyright holder. Environmental Challenges BUSINESS SOLUTIONS ® www.earthcon.com Remedial Plan 1.Sheet pile cut-off wall to block the pathway for further creosote migration from the site into the creek 2.Removal of creosote impacted creek sediments 3.Creek bank stabilization

16. © 2015 EarthCon Consultants, Inc. All rights reserved. This material may not be reproduced, displayed, modified or distributed without the express prior written permission of the copyright holder. Environmental Challenges BUSINESS SOLUTIONS ® www.earthcon.com Site Timeline Feb: USACE NWP No. 38 Nov: Begin remediating ~1,380’ section of Cr. Dec 11: heavy rains damage inflatable dam Nov: mtg with MDEQ Finalize remedy June: creosote globules obv in Foster Cr Nov: Topo map of Foster Cr developed Dec: Cr assessment 20082010 2011 Mar: 7” rain in 24-hrs Apr: 1 st bag wall installed June: 2 nd bag wall installed Dec: 5” rain in 48-hrs 2013 Jan: storm event, higher stream flows than Dec 2011 event June: enhanced Bag Wall 2, install gabion baskets 2014 Feb/Mar: 2 heavy rainfall events resulted in 200-yr flood event 2006

17. © 2015 EarthCon Consultants, Inc. All rights reserved. This material may not be reproduced, displayed, modified or distributed without the express prior written permission of the copyright holder. Environmental Challenges BUSINESS SOLUTIONS ® www.earthcon.com Sheet Pile Cut-Off Wall

18. © 2015 EarthCon Consultants, Inc. All rights reserved. This material may not be reproduced, displayed, modified or distributed without the express prior written permission of the copyright holder. Environmental Challenges BUSINESS SOLUTIONS ® www.earthcon.com Sheet Pile Cut-Off Wall 45’ long sheet pile pairs Vibratory hammer driving pilings into underlying Miocene Clay

19. © 2015 EarthCon Consultants, Inc. All rights reserved. This material may not be reproduced, displayed, modified or distributed without the express prior written permission of the copyright holder. Environmental Challenges BUSINESS SOLUTIONS ® www.earthcon.com Section D-D’

20. © 2015 EarthCon Consultants, Inc. All rights reserved. This material may not be reproduced, displayed, modified or distributed without the express prior written permission of the copyright holder. Environmental Challenges BUSINESS SOLUTIONS ® www.earthcon.com Sheet Pile Cut-Off Wall

21. © 2015 EarthCon Consultants, Inc. All rights reserved. This material may not be reproduced, displayed, modified or distributed without the express prior written permission of the copyright holder. Environmental Challenges BUSINESS SOLUTIONS ® www.earthcon.com Sheet Pile Cut-Off Wall

22. © 2015 EarthCon Consultants, Inc. All rights reserved. This material may not be reproduced, displayed, modified or distributed without the express prior written permission of the copyright holder. Environmental Challenges BUSINESS SOLUTIONS ® www.earthcon.com Sediment Remediation Materials selected for the remediation included: Organoclay; Reactive core mat (RCM); and TerraCell® Cellular Confinement System.

23. © 2015 EarthCon Consultants, Inc. All rights reserved. This material may not be reproduced, displayed, modified or distributed without the express prior written permission of the copyright holder. Environmental Challenges BUSINESS SOLUTIONS ® www.earthcon.com Sediment Remediation

24. © 2015 EarthCon Consultants, Inc. All rights reserved. This material may not be reproduced, displayed, modified or distributed without the express prior written permission of the copyright holder. Environmental Challenges BUSINESS SOLUTIONS ® www.earthcon.com Sediment Remediation

25. © 2015 EarthCon Consultants, Inc. All rights reserved. This material may not be reproduced, displayed, modified or distributed without the express prior written permission of the copyright holder. Environmental Challenges BUSINESS SOLUTIONS ® www.earthcon.com Creek Diversion

26. © 2015 EarthCon Consultants, Inc. All rights reserved. This material may not be reproduced, displayed, modified or distributed without the express prior written permission of the copyright holder. Environmental Challenges BUSINESS SOLUTIONS ® www.earthcon.com Sediment Remediation

27. © 2015 EarthCon Consultants, Inc. All rights reserved. This material may not be reproduced, displayed, modified or distributed without the express prior written permission of the copyright holder. Environmental Challenges BUSINESS SOLUTIONS ® www.earthcon.com Sediment Removal Bladder dam set in place Bladder dam filled

28. © 2015 EarthCon Consultants, Inc. All rights reserved. This material may not be reproduced, displayed, modified or distributed without the express prior written permission of the copyright holder. Environmental Challenges BUSINESS SOLUTIONS ® www.earthcon.com Temporary Sheet Pile Dam

29. © 2015 EarthCon Consultants, Inc. All rights reserved. This material may not be reproduced, displayed, modified or distributed without the express prior written permission of the copyright holder. Environmental Challenges BUSINESS SOLUTIONS ® www.earthcon.com Turbidity Curtain

30. © 2015 EarthCon Consultants, Inc. All rights reserved. This material may not be reproduced, displayed, modified or distributed without the express prior written permission of the copyright holder. Environmental Challenges BUSINESS SOLUTIONS ® www.earthcon.com Groundwater in Excavation

31. © 2015 EarthCon Consultants, Inc. All rights reserved. This material may not be reproduced, displayed, modified or distributed without the express prior written permission of the copyright holder. Environmental Challenges BUSINESS SOLUTIONS ® www.earthcon.com Creosote in Excavation

32. © 2015 EarthCon Consultants, Inc. All rights reserved. This material may not be reproduced, displayed, modified or distributed without the express prior written permission of the copyright holder. Environmental Challenges BUSINESS SOLUTIONS ® www.earthcon.com Pumping Creosote

33. © 2015 EarthCon Consultants, Inc. All rights reserved. This material may not be reproduced, displayed, modified or distributed without the express prior written permission of the copyright holder. Environmental Challenges BUSINESS SOLUTIONS ® www.earthcon.com Organoclay

34. © 2015 EarthCon Consultants, Inc. All rights reserved. This material may not be reproduced, displayed, modified or distributed without the express prior written permission of the copyright holder. Environmental Challenges BUSINESS SOLUTIONS ® www.earthcon.com Reactive Core Mat (RCM)

35. © 2015 EarthCon Consultants, Inc. All rights reserved. This material may not be reproduced, displayed, modified or distributed without the express prior written permission of the copyright holder. Environmental Challenges BUSINESS SOLUTIONS ® www.earthcon.com Sealing RCM Seams

36. © 2015 EarthCon Consultants, Inc. All rights reserved. This material may not be reproduced, displayed, modified or distributed without the express prior written permission of the copyright holder. Environmental Challenges BUSINESS SOLUTIONS ® www.earthcon.com Scour Prevention

37. © 2015 EarthCon Consultants, Inc. All rights reserved. This material may not be reproduced, displayed, modified or distributed without the express prior written permission of the copyright holder. Environmental Challenges BUSINESS SOLUTIONS ® www.earthcon.com Backfilling over Geogrid

38. © 2015 EarthCon Consultants, Inc. All rights reserved. This material may not be reproduced, displayed, modified or distributed without the express prior written permission of the copyright holder. Environmental Challenges BUSINESS SOLUTIONS ® www.earthcon.com View Upstream

39. © 2015 EarthCon Consultants, Inc. All rights reserved. This material may not be reproduced, displayed, modified or distributed without the express prior written permission of the copyright holder. Environmental Challenges BUSINESS SOLUTIONS ® www.earthcon.com Remediation Complete In summary: ~14,000 yd 3 excavated sediment ~555 loads of clean, imported fill material ~25,500 lbs of low permeability organoclay 59 rolls of RCM 283 pieces of geogrid

40. © 2015 EarthCon Consultants, Inc. All rights reserved. This material may not be reproduced, displayed, modified or distributed without the express prior written permission of the copyright holder. Environmental Challenges BUSINESS SOLUTIONS ® www.earthcon.com Site Timeline Feb: USACE NWP No. 38 Nov: Begin remediating ~1,380’ section of Cr. Dec 11: heavy rains damage inflatable dam Nov: mtg with MDEQ Finalize remedy June: creosote globules obv in Foster Cr Nov: Topo map of Foster Cr developed Dec: Cr assessment 20082010 2011 Mar: 7” rain in 24-hrs Apr: 1 st bag wall installed June: 2 nd bag wall installed Dec: 5” rain in 48-hrs 2013 Jan: storm event, higher stream flows than Dec 2011 event June: enhanced Bag Wall 2, install gabion baskets 2014 Feb/Mar: 2 heavy rainfall events resulted in 200-yr flood event 2006

41. © 2015 EarthCon Consultants, Inc. All rights reserved. This material may not be reproduced, displayed, modified or distributed without the express prior written permission of the copyright holder. Environmental Challenges BUSINESS SOLUTIONS ® www.earthcon.com Bag Wall Installation Trench for the foundation of the wall Bags interwoven

42. © 2015 EarthCon Consultants, Inc. All rights reserved. This material may not be reproduced, displayed, modified or distributed without the express prior written permission of the copyright holder. Environmental Challenges BUSINESS SOLUTIONS ® www.earthcon.com Bag Walls with Vegetation

43. © 2015 EarthCon Consultants, Inc. All rights reserved. This material may not be reproduced, displayed, modified or distributed without the express prior written permission of the copyright holder. Environmental Challenges BUSINESS SOLUTIONS ® www.earthcon.com Site Timeline Feb: USACE NWP No. 38 Nov: Begin remediating ~1,380’ section of Cr. Dec 11: heavy rains damage inflatable dam Nov: mtg with MDEQ Finalize remedy June: creosote globules obv in Foster Cr Nov: Topo map of Foster Cr developed Dec: Cr assessment 20082010 2011 Mar: 7” rain in 24-hrs Apr: 1 st bag wall installed June: 2 nd bag wall installed Dec: 5” rain in 48-hrs 2013 Jan: storm event, higher stream flows than Dec 2011 event June: enhanced Bag Wall 2, install gabion baskets 2014 Feb/Mar: 2 heavy rainfall events resulted in 200-yr flood event 2006

44. © 2015 EarthCon Consultants, Inc. All rights reserved. This material may not be reproduced, displayed, modified or distributed without the express prior written permission of the copyright holder. Environmental Challenges BUSINESS SOLUTIONS ® www.earthcon.com January 2013

45. © 2015 EarthCon Consultants, Inc. All rights reserved. This material may not be reproduced, displayed, modified or distributed without the express prior written permission of the copyright holder. Environmental Challenges BUSINESS SOLUTIONS ® www.earthcon.com

46. © 2015 EarthCon Consultants, Inc. All rights reserved. This material may not be reproduced, displayed, modified or distributed without the express prior written permission of the copyright holder. Environmental Challenges BUSINESS SOLUTIONS ® www.earthcon.com Site Timeline Feb: USACE NWP No. 38 Nov: Begin remediating ~1,380’ section of Cr. Dec 11: heavy rains damage inflatable dam Nov: mtg with MDEQ Finalize remedy June: creosote globules obv in Foster Cr Nov: Topo map of Foster Cr developed Dec: Cr assessment 20082010 2011 Mar: 7” rain in 24-hrs Apr: 1 st bag wall installed June: 2 nd bag wall installed Dec: 5” rain in 48-hrs 2013 Jan: storm event, higher stream flows than Dec 2011 event June: enhanced Bag Wall 2, install gabion baskets 2014 Feb/Mar: 2 heavy rainfall events resulted in 200-yr flood event 2006

47. © 2015 EarthCon Consultants, Inc. All rights reserved. This material may not be reproduced, displayed, modified or distributed without the express prior written permission of the copyright holder. Environmental Challenges BUSINESS SOLUTIONS ® www.earthcon.com February 2014

48. © 2015 EarthCon Consultants, Inc. All rights reserved. This material may not be reproduced, displayed, modified or distributed without the express prior written permission of the copyright holder. Environmental Challenges BUSINESS SOLUTIONS ® www.earthcon.com February 2014

49. © 2015 EarthCon Consultants, Inc. All rights reserved. This material may not be reproduced, displayed, modified or distributed without the express prior written permission of the copyright holder. Environmental Challenges BUSINESS SOLUTIONS ® www.earthcon.com March 2014

50. © 2015 EarthCon Consultants, Inc. All rights reserved. This material may not be reproduced, displayed, modified or distributed without the express prior written permission of the copyright holder. Environmental Challenges BUSINESS SOLUTIONS ® www.earthcon.com March 2014

51. © 2015 EarthCon Consultants, Inc. All rights reserved. This material may not be reproduced, displayed, modified or distributed without the express prior written permission of the copyright holder. Environmental Challenges BUSINESS SOLUTIONS ® www.earthcon.com March 2014

52. © 2015 EarthCon Consultants, Inc. All rights reserved. This material may not be reproduced, displayed, modified or distributed without the express prior written permission of the copyright holder. Environmental Challenges BUSINESS SOLUTIONS ® www.earthcon.com Storm Aftermath The crest of the bag walls was intact and stable with no significant erosion or channeling observed Good vegetative growth remained on the bag walls Geogrid was exposed in limited areas but remained intact

53. © 2015 EarthCon Consultants, Inc. All rights reserved. This material may not be reproduced, displayed, modified or distributed without the express prior written permission of the copyright holder. Environmental Challenges BUSINESS SOLUTIONS ® www.earthcon.com March 2014

54. © 2015 EarthCon Consultants, Inc. All rights reserved. This material may not be reproduced, displayed, modified or distributed without the express prior written permission of the copyright holder. Environmental Challenges BUSINESS SOLUTIONS ® www.earthcon.com Storm Aftermath Some scattered boulders had been scoured from the rip-rap at the toe of the bag walls The gabions along the toe of the wall were aligned and intact A comparison of the 2013 survey data to the 2014 and 2015 survey data shows no movement of the bag walls THE REMEDY HELD!!!

55. © 2015 EarthCon Consultants, Inc. All rights reserved. This material may not be reproduced, displayed, modified or distributed without the express prior written permission of the copyright holder. Environmental Challenges BUSINESS SOLUTIONS ® www.earthcon.com Foster Creek Post-Remediation

56. © 2015 EarthCon Consultants, Inc. All rights reserved. This material may not be reproduced, displayed, modified or distributed without the express prior written permission of the copyright holder. Environmental Challenges BUSINESS SOLUTIONS ® www.earthcon.com Questions?

57. © 2015 EarthCon Consultants, Inc. All rights reserved. This material may not be reproduced, displayed, modified or distributed without the express prior written permission of the copyright holder. Environmental Challenges BUSINESS SOLUTIONS ® www.earthcon.com Thank You! EarthCon Thanks You for your time and interest. Kristen Rivera krivera@earthcon.comkrivera@earthcon.com Please contact us for additional information, and please visit our website at: www.earthcon.com THANKS!