12/7/2017. Kinder Morgan Bank Cap in Portland Harbor Path to Implementation CH2M HILL. Personal Information. Linnton Terminal Bank

Transcription

1 Kinder Morgan Bank Cap in Portland Harbor Path to Implementation Jeff Gentry, P.E./CH2M December 5, 2017 Acknowledgments: Scott Martin/Kinder Morgan Keith Sheets/CH2M Personal Information Principle Technologist Focus on NAPL on shoreline and in sediment 30 years with CH2M HILL in Corvallis and Portland, OR Last five years as the lead technical consultant for EPA on the Gowanus Canal Published on NAPL mobility, LEAF and ISS in sediment CH2M HILL Started in Corvallis, OR in 1946 Portland, OR office opened in 1964 Portland, OR is the second largest CH2M office Potential to merge with Jacobs in December Linnton Terminal Bank 1,052 feet of river bank 100 feet of river bank has intermittent sheen discharge 3 ROD includes 19,472 lineal ft of river bank 3 1

2 Bank pictures in target area Low Water High Water Barrier Wall Barrier wall installed to block NAPL flow path to the river Monitoring has shown wall effective; sheen reduced, but intermittent still persists in blue area 5 Conceptual Site Model NAPL Groundwater discharge zone Upland NAPL release migrated to the river NAPL Stranded After Barrier Wall Installed Low to no Groundwater Flow Zone 6 2

3 Adapting to Changing Regulatory Approach Prior to Record of Decision Upland source control evaluation under DEQ oversight Interim measure barrier wall installed in 2011 Address intermittent sheen caused by wedge of impacted soil riverward of barrier wall Planned measure to address sheen only and keep out of river After ROD Site identified for riverbank remedial action in ROD Riverbank remedial technologies identified in ROD Excavation Significantly Augmented Cap Both sheen and pore water impacts need to be addressed DEQ still lead agency 7 Which process applies for Remedy Selection? Joint source control agreement specified an Engineering Evaluation/Cost Analysis for source control decisions Portland Harbor ROD had a specific technology criteria for Riverbank remedies EPA requested a more formal FS analysis but DEQ did not agree 8 Design Criteria for Cap ROD provides design criteria for the following cap attributes NAPL Areas of groundwater PRG exceedance Structures (not applicable) Debris (not applicable) Armor and Habitat Slope Flood rise and navigation Land and in river use (not applicable) Cap design address or balance the bolded items 9 3

4 Innovation from The University Consortium The University Consortium has been around 30 years and has made significant contributions to groundwater research Funded research on sheen control technologies Colorado State University has a patent pending on the Oleophilic bio barrier as a result of this research CH2M is a contributing member to the group Fall 2017 Focus meeting on interactions at the groundwater surface water interface so expect more from this group in the future for more information 10 Cap Design NAPL Cap design will include organoclay, other reactive material, and/or low permeability material, as necessary,.. The cap includes an oleophilic bio barrier new technology being developed for sheen control The oleophilic bio barrier is a reactive material where NAPL is trapped and allowed to biodegrade and meets the other reactive material ROD design requirement for NAPL 11 Photo courtesy of Colorado State University Cap Design Groundwater Discharge Cap design will require the use of activated carbon, other reactive material, and/or low permeability materials, as necessary,.. Cleanup levels are presented in the ROD Groundwater discharge and pore water concentration data were available Conservative assumptions to design the active cap layer using CapSim A six inch layer of a mixture of 20% activated carbon and sand can treat discharge for 100 years 12 4

5 Cap Design Slope Sediment caps will be designed to remain in place.. This may require removal of material to lessen the slope angle or incorporation of buttresses at the base of the slope to maintain stability and promote establishing habitats. River bank slopes would be laid back to as close as a 5H:1V slope as practicable given site specific conditions Slope of 5:1 not reasonable at this site because of large amounts of fill that would be needed City required geotechnical analysis of the slope stability for the permit exception documentation 30 ft top of bank 20 ft ~6 ft 13 Cap Design Armor Caps will be constructed with sufficient armor..to prevent erosion Engineered beach mix layer, consisting of rounded gravel typically 2.5 inches or less would be applied to the uppermost layer of all caps These criteria likely conflict for most riverbank sites on the Portland Harbor ROD prefers habitat friendly cap surfaces Preliminary design of armor to withstand waves indicates Class 100 Rip rap needed for this site 14 Cap Design Flood Rise and Navigation Caps will be designed to avoid adverse impacts to the floodway,... City of Portland administers FEMA regulations: No net fill No net rise of flood waters (<0.004 ft) No fill accomplished by removal of material inside the flood plane No rise analysis performed that showed no net rise 15 5

6 Cap Design Habitat If loss of habitat occurs, compensatory mitigation will be undertaken. The details of any necessary compensatory mitigation will be developed during remedial design for the purpose of offsetting authorized impacts on Site wherever possible. Extent of bank armor was identified during survey Unarmored beach habitat area included in the cap area Removal of rip rap in other areas required if beach area covered with rip rap 16 Permitting In Water Work Constraints ROD requirements extended project into the nearshore areas 404/401 JPA Permit NMFS indicated that a biological assessment for the application would be needed for in water work In March 2017, notified that a BA would be needed and an ~180 day review time Adaptive solution, build what you can above the water in 2017! 17 City Permitting Project was exempt from greenway and site development permit, but Demonstration required that substantive requirements had been met which include Project description Stamped geotechnical report Stamped flood rise analysis Contaminated media management plan $7,000 review fee 18 6

7 Summary of Design Requirements NAPL Use oleophilic clay or other reactive materials Groundwater Discharge Meet pore water PRG s Use carbon or other adsorbents Armor Use beach mix but only if it will not erode Habitat Compensatory mitigation required for beach habitat loss Slope 5:1 slope preferred but if beach layer cannot be established, slope less important Flood Rise No net fill No net rise Geotech Bank Stability Analysis 19 Cap design summary The significantly augmented cap contains the following layers Leveling layer Oleophilic bio barrier layer Granular activated carbon gravel (6 inches) Geotextile separation layer Armor Layer (24 inches) Overall thickness, 3 foot allowance 20 Oleophilic Bio Barrier Design Sheen area and intensity was measured over Sheen volume 1 to 15 ml Capacity >5,000 sheen events without degradation Sheen discharge primarily from 10 to 13 feet Overlaps in OBB panels designed to allow multiple layers 10 to 13 feet 21 7

8 Design Design relatively simple once all requirements identified 15 drawings 25 specification sections Completed in eight weeks Issued to bid August 2017 Work area was expanded to remove fill from flood plane in separate area of facility 22 Design and Construction Remove existing rip rap. Level slope with granular fill Install geogrid in anchor trench 23 Design and Construction Grade geogrid with crown in middle. Install Oleophilic Bio Barrier with overlaps Place reused and new rip rap 24 Place carbon granular fill mixture 8

9 Before and After 25 Each of these projects will take a team of professionals Person Role Keith Sheets Project Manager Jeff Gentry. P.E. Engineer of Record Carrie Andrews COE and DSL permits Paul Seilo City permit exclusion Dr. Ali Salter Blanc Project Scientist Brad Ostapkowicz, P.E. Project Engineer Richard Alesci, P.E. Project Engineer Jennifer Ulrich Project Geologist Teresa Himmer Pore Water SME Dr. Bhawana Sharma CAPSIM SME Dave Dailer, P.E. (semi retired) Jedi Geotech Joe Hurliman Survey Mark Anderson, P.E. Flood Rise Analysis 26 Red entries are from CH2M Portland office Tasks include Remedy selection with both DEQ and EPA Permitting through ACOE, DSL, DEQ, City of Portland Geotechnical engineers Hydraulic engineers Construction provided by Arcadis with LKE Corporation as the earth work subcontractor Summary and Observations 100 Lineal feet of river bank capped 0.5% of total bank cap remedy! Remedy selection process for banks after ROD unclear Process could be simplified by just applying the ROD design criteria City permit remedial action exempt review process is no different from getting permits Remedial Action Exempt Review Application = 224 pages Flood rise analysis is important but are there thresholds where it is not needed? Will every in water project require its own biological assessment? 27 9