© 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. REMEDIAL APPROACH DESIGNED WITH POTENTIAL ADVERSE WEATHER CONDITIONS IN MIND: A CASE STUDY OF AN IMPACTED CREEK

© 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 ® Former Wood Treatment Facility Wilkinson and Amite Counties, Mississippi, near the town of Crosby, adjacent to Foster Creek

© 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 ® Site Location

© 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 ® 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

© 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 ® 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

© 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 ® : recovery wells installed GWTS constructed 1986: Beginning of corrective action Wood treating operations end Wood treating operations begin 1985 Presence of creosote observed in Foster Cr 1986 Site Timeline

© 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 ® Distribution of NAPL (ca 1990) N

© 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 ® Remediation System

© 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 ® Spray Fields

© 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 ® 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 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

© 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 ® Foster Creek

© 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 ® Foster Creek

© 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 ® Creek Assessment

© 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 ® 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 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

© 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 ® 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

© 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 ® 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 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

© 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 ® Sheet Pile Cut-Off Wall

© 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 ® Sheet Pile Cut-Off Wall 45’ long sheet pile pairs Vibratory hammer driving pilings into underlying Miocene Clay

© 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 ® Section D-D’

© 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 ® Sheet Pile Cut-Off Wall

© 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 ® Sheet Pile Cut-Off Wall

© 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 ® Sediment Remediation Materials selected for the remediation included: Organoclay; Reactive core mat (RCM); and TerraCell® Cellular Confinement System.

© 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 ® Sediment Remediation

© 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 ® Sediment Remediation

© 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 ® Creek Diversion

© 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 ® Sediment Remediation

© 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 ® Sediment Removal Bladder dam set in place Bladder dam filled

© 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 ® Temporary Sheet Pile Dam

© 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 ® Turbidity Curtain

© 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 ® Groundwater in Excavation

© 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 ® Creosote in Excavation

© 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 ® Pumping Creosote

© 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 ® Organoclay

© 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 ® Reactive Core Mat (RCM)

© 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 ® Sealing RCM Seams

© 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 ® Scour Prevention

© 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 ® Backfilling over Geogrid

© 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 ® View Upstream

© 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 ® 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

© 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 ® 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 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

© 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 ® Bag Wall Installation Trench for the foundation of the wall Bags interwoven

© 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 ® Bag Walls with Vegetation

© 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 ® 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 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

© 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 ® January 2013

© 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 ®

© 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 ® 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 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

© 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 ® February 2014

© 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 ® February 2014

© 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 ® March 2014

© 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 ® March 2014

© 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 ® March 2014

© 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 ® 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

© 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 ® March 2014

© 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 ® 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!!!

© 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 ® Foster Creek Post-Remediation

© 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 ® Questions?

© 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 ® Thank You! EarthCon Thanks You for your time and interest. Kristen Rivera Please contact us for additional information, and please visit our website at: THANKS!