![Page 1: Kwasi Badu-Tweneboah, Ph.D., P.E. – Geosyntec Consultants Jacksonville, Florida, USA Kenneth W. Cargill, P.E. – KW Cargill, P.A.. Punta Gorda, Florida,](https://reader035.vdocument.in/reader035/viewer/2022062519/5697c0261a28abf838cd5f80/html5/thumbnails/1.jpg)
Kwasi Badu-Tweneboah, Ph.D., P.E. – Geosyntec Consultants Jacksonville, Florida, USA
Kenneth W. Cargill, P.E. – KW Cargill, P.A..Punta Gorda, Florida, USA
Challenges of Dredging and Material Disposal at a LNG
Facility in Savannah Harbor, Georgia, USA
![Page 2: Kwasi Badu-Tweneboah, Ph.D., P.E. – Geosyntec Consultants Jacksonville, Florida, USA Kenneth W. Cargill, P.E. – KW Cargill, P.A.. Punta Gorda, Florida,](https://reader035.vdocument.in/reader035/viewer/2022062519/5697c0261a28abf838cd5f80/html5/thumbnails/2.jpg)
Presentation Outline• Project Location and Background• The Business – LNG Operations• Contract and Permit Requirements• Dredging Challenges• Evaluation of Dredging Options• Disposal Challenges• Prediction of DMCA Life• Evaluation of Disposal Options• Summary
2
2
![Page 3: Kwasi Badu-Tweneboah, Ph.D., P.E. – Geosyntec Consultants Jacksonville, Florida, USA Kenneth W. Cargill, P.E. – KW Cargill, P.A.. Punta Gorda, Florida,](https://reader035.vdocument.in/reader035/viewer/2022062519/5697c0261a28abf838cd5f80/html5/thumbnails/3.jpg)
Project Location and Background• Located 5 miles
East Northeast of Savannah
• Bounded by the Savannah River, South Channel, and Intracoastal waterways
• River Mile 7.5• Lower Savannah
Harbor• Most seaward
port facility 3
![Page 4: Kwasi Badu-Tweneboah, Ph.D., P.E. – Geosyntec Consultants Jacksonville, Florida, USA Kenneth W. Cargill, P.E. – KW Cargill, P.A.. Punta Gorda, Florida,](https://reader035.vdocument.in/reader035/viewer/2022062519/5697c0261a28abf838cd5f80/html5/thumbnails/4.jpg)
The Business – LNG Operations
• Storage capacity 11.5 Bcfe• Delivery rate capacity:
– Firm delivery rate 1,518 MMcf/d– Maximum delivery rate 1,755 MMcf/d
D-1D-4
D-5
D-6(future)
D-2D-3
4
![Page 5: Kwasi Badu-Tweneboah, Ph.D., P.E. – Geosyntec Consultants Jacksonville, Florida, USA Kenneth W. Cargill, P.E. – KW Cargill, P.A.. Punta Gorda, Florida,](https://reader035.vdocument.in/reader035/viewer/2022062519/5697c0261a28abf838cd5f80/html5/thumbnails/5.jpg)
Relevant Infrastructure• Turning Basin – Approx. 33 acres conforming with U.S.
Coast Guard minimum (FERC Recommendation)
• Ship Slip – Approx. 44 acres, berths for 2 ships simultaneously
• DMCA 1 – Approx. 130 acres, dike last raised 2011, current dike elevation 50 ft MLW, being used for disposal
• DMCA 2 – Approx. 120 acres, dike last raised 2009, being intensively managed for drying and material harvesting, current dike elevation 44 ft MLW
5
![Page 6: Kwasi Badu-Tweneboah, Ph.D., P.E. – Geosyntec Consultants Jacksonville, Florida, USA Kenneth W. Cargill, P.E. – KW Cargill, P.A.. Punta Gorda, Florida,](https://reader035.vdocument.in/reader035/viewer/2022062519/5697c0261a28abf838cd5f80/html5/thumbnails/6.jpg)
Dual Ship Off-loading
6
![Page 7: Kwasi Badu-Tweneboah, Ph.D., P.E. – Geosyntec Consultants Jacksonville, Florida, USA Kenneth W. Cargill, P.E. – KW Cargill, P.A.. Punta Gorda, Florida,](https://reader035.vdocument.in/reader035/viewer/2022062519/5697c0261a28abf838cd5f80/html5/thumbnails/7.jpg)
2008 Elba IslandAerial Photograph
7
![Page 8: Kwasi Badu-Tweneboah, Ph.D., P.E. – Geosyntec Consultants Jacksonville, Florida, USA Kenneth W. Cargill, P.E. – KW Cargill, P.A.. Punta Gorda, Florida,](https://reader035.vdocument.in/reader035/viewer/2022062519/5697c0261a28abf838cd5f80/html5/thumbnails/8.jpg)
Dredged Material Containment AreasDMCA 1~ 130
ac
DMCA 2~ 120 ac
Sedimentation Pond
Weir Outlet
Elba Island Aerial Photograph(August 2011)
8
DMCA 1~ 130
ac
DMCA 2~ 120 acSedimentatio
n Pond
Elba Island Aerial Photograph(August 2011)
![Page 9: Kwasi Badu-Tweneboah, Ph.D., P.E. – Geosyntec Consultants Jacksonville, Florida, USA Kenneth W. Cargill, P.E. – KW Cargill, P.A.. Punta Gorda, Florida,](https://reader035.vdocument.in/reader035/viewer/2022062519/5697c0261a28abf838cd5f80/html5/thumbnails/9.jpg)
Contract and Permit Requirements
• Typical 1-month notification of LNG Tanker ship coming
• Huge Financial Penalty if ship cannot come or dock
• Maintain required dredge depths year round– Ship Slip: -42 ft MLW min. (-46 ft max.)– Turning Basin: -38 ft MLW min. (-42 ft max.)– Dredging ship slip every 2 to 3 months– Annual total volume ≈ 1 million cubic yards 9
![Page 10: Kwasi Badu-Tweneboah, Ph.D., P.E. – Geosyntec Consultants Jacksonville, Florida, USA Kenneth W. Cargill, P.E. – KW Cargill, P.A.. Punta Gorda, Florida,](https://reader035.vdocument.in/reader035/viewer/2022062519/5697c0261a28abf838cd5f80/html5/thumbnails/10.jpg)
Dredging Challenges• Rapid Sediment Accumulation
– Loading Conditions of Savannah River– Ship Slip and Turning Basin acting as Bath Tubs (Sinks)
• Permit Renewal Challenges– 20-month (in lieu of 5-yr) permit issued in July 2011– New renewal application tied with upper harbor users– Water quality and EFH conditions - NMFS, USFWS,
GAEPD, SCDHEC• Procurement and Mobilization of Dredging
Contractor– One hydraulic cutterhead dredger in Savannah River– Use by USACE and other harbor users– Scheduling of next dredging event
• Disposal Issues 10
![Page 11: Kwasi Badu-Tweneboah, Ph.D., P.E. – Geosyntec Consultants Jacksonville, Florida, USA Kenneth W. Cargill, P.E. – KW Cargill, P.A.. Punta Gorda, Florida,](https://reader035.vdocument.in/reader035/viewer/2022062519/5697c0261a28abf838cd5f80/html5/thumbnails/11.jpg)
Dredging Challenges
11
![Page 12: Kwasi Badu-Tweneboah, Ph.D., P.E. – Geosyntec Consultants Jacksonville, Florida, USA Kenneth W. Cargill, P.E. – KW Cargill, P.A.. Punta Gorda, Florida,](https://reader035.vdocument.in/reader035/viewer/2022062519/5697c0261a28abf838cd5f80/html5/thumbnails/12.jpg)
Evaluation of Dredging Options• Long-term contract with hydraulic cutterhead dredging
contractor – Lump sum contract ($5/cy to $10/cy in lieu of typical $3/cy to
$4.50/cy) – Continual negotiations with USACE to release dredge
• Purchase and operate its own dredge • Contract dredging operations to a non-dredging contractor
• Pursue alternative dredging solutions
– Use of I-beam bed leveling – agitation dredging• Nationwide Permit (NW) 5 issued by USACE as research study • Four trial tests completed to date – results being analyzed
– Use of clamshell bucket dredging and ocean disposal• Permitting Challenges• Tier III testing and analyses 12
![Page 13: Kwasi Badu-Tweneboah, Ph.D., P.E. – Geosyntec Consultants Jacksonville, Florida, USA Kenneth W. Cargill, P.E. – KW Cargill, P.A.. Punta Gorda, Florida,](https://reader035.vdocument.in/reader035/viewer/2022062519/5697c0261a28abf838cd5f80/html5/thumbnails/13.jpg)
Disposal Challenges• Long-Term Dredged Material Management Plan
(DMMP)– Prediction of DMCAs Life using Corps’ PSDDF
software program• Impact of Increased Frequency of Dredging
– Rapid Filling of DMCAs– Less Time for consolidation and desiccation – Changes to Dike Raising schedules
• Dike Raising Constraints– Maximum dike height of 62 to 68 ft MLW– Stability Constraints– Availability of fill material 13
![Page 14: Kwasi Badu-Tweneboah, Ph.D., P.E. – Geosyntec Consultants Jacksonville, Florida, USA Kenneth W. Cargill, P.E. – KW Cargill, P.A.. Punta Gorda, Florida,](https://reader035.vdocument.in/reader035/viewer/2022062519/5697c0261a28abf838cd5f80/html5/thumbnails/14.jpg)
Prediction of DMCA LifeUsing Corps Model PSDDF
Cases CommentsDredging
Event
Thickness Deposited
(ft)
Estimated Life Expectancy
DMCA 1 DMCA 2
DMCA 1
DMCA 2
62 ft 68 ft 62 ft 68 ft
Case 1
2 dredging events per year: SS and TB
1 April 3.94 4.22 Apr-25Apr-29
Oct-24
Oct-28
2 October 3.94 4.22
Case 2
3 dredging events per year: SS and TB
1 March 2.63 2.82 Jul-25Mar-29
Nov-24
Nov-28
2 July 2.63 2.82
3Novembe
r2.63 2.82
Case 3
3 dredging events per year: SS
1 March 1.07 1.15 Mar-49 - Jul-50 -
2 July 1.07 1.15
3Novembe
r1.07 1.15
Case 4
3 dredging events per year: SS
2 dredging events per year: TB
1 March 3.4 3.65 Mar-25Mar-29
Mar-27
Nov-28
2 July 3.4 3.65
3Novembe
r1.07 1.15
Notes: SS = Ship Slip; TB = Turning Basin
14
![Page 15: Kwasi Badu-Tweneboah, Ph.D., P.E. – Geosyntec Consultants Jacksonville, Florida, USA Kenneth W. Cargill, P.E. – KW Cargill, P.A.. Punta Gorda, Florida,](https://reader035.vdocument.in/reader035/viewer/2022062519/5697c0261a28abf838cd5f80/html5/thumbnails/15.jpg)
15
![Page 16: Kwasi Badu-Tweneboah, Ph.D., P.E. – Geosyntec Consultants Jacksonville, Florida, USA Kenneth W. Cargill, P.E. – KW Cargill, P.A.. Punta Gorda, Florida,](https://reader035.vdocument.in/reader035/viewer/2022062519/5697c0261a28abf838cd5f80/html5/thumbnails/16.jpg)
Evaluation of Disposal Options• Bed leveling in ship slip
o Nationwide Permit (NW) 5 issued – results of trial tests being analyzed
o Allow more drying time in DMCA by increasing time between dredging
• Intensive management of DMCA drainage and dredged material harvesting o Concepts developed during last DMCA 1 dike raisingo Concepts currently being implemented in DMCA 2o Final objective is system steady state where volume
capacity of DMCA is perpetually restored between dredging
• Negotiations with USACE – Use of SC DMCAs for dredged material disposal– Ship Slip and Turning Basin are for a single user
• Ocean Disposal
16
![Page 17: Kwasi Badu-Tweneboah, Ph.D., P.E. – Geosyntec Consultants Jacksonville, Florida, USA Kenneth W. Cargill, P.E. – KW Cargill, P.A.. Punta Gorda, Florida,](https://reader035.vdocument.in/reader035/viewer/2022062519/5697c0261a28abf838cd5f80/html5/thumbnails/17.jpg)
Development of Interior Borrow Pits
17
![Page 18: Kwasi Badu-Tweneboah, Ph.D., P.E. – Geosyntec Consultants Jacksonville, Florida, USA Kenneth W. Cargill, P.E. – KW Cargill, P.A.. Punta Gorda, Florida,](https://reader035.vdocument.in/reader035/viewer/2022062519/5697c0261a28abf838cd5f80/html5/thumbnails/18.jpg)
Concept of Intensive DMCA Management
• Rapid removal of decanted water immediately after end of dredging and constant removal of drainage
• Use of specialty equipment to create and enhance drainage pathways
• Early and continual removal of dredged material slurry at perimeter to promote interior desiccated crust
• Early and continual removal of desiccated crust on perimeter of DMCA
• Development of interior borrow pits for material mining as possible
• Removal of desiccated and consolidated material and hauling to stockpile areas 18
![Page 19: Kwasi Badu-Tweneboah, Ph.D., P.E. – Geosyntec Consultants Jacksonville, Florida, USA Kenneth W. Cargill, P.E. – KW Cargill, P.A.. Punta Gorda, Florida,](https://reader035.vdocument.in/reader035/viewer/2022062519/5697c0261a28abf838cd5f80/html5/thumbnails/19.jpg)
19
Concept of Intensive DMCA Management
![Page 20: Kwasi Badu-Tweneboah, Ph.D., P.E. – Geosyntec Consultants Jacksonville, Florida, USA Kenneth W. Cargill, P.E. – KW Cargill, P.A.. Punta Gorda, Florida,](https://reader035.vdocument.in/reader035/viewer/2022062519/5697c0261a28abf838cd5f80/html5/thumbnails/20.jpg)
20
Concept of Intensive DMCA Management
![Page 21: Kwasi Badu-Tweneboah, Ph.D., P.E. – Geosyntec Consultants Jacksonville, Florida, USA Kenneth W. Cargill, P.E. – KW Cargill, P.A.. Punta Gorda, Florida,](https://reader035.vdocument.in/reader035/viewer/2022062519/5697c0261a28abf838cd5f80/html5/thumbnails/21.jpg)
Concept of Intensive DMCA Management
![Page 22: Kwasi Badu-Tweneboah, Ph.D., P.E. – Geosyntec Consultants Jacksonville, Florida, USA Kenneth W. Cargill, P.E. – KW Cargill, P.A.. Punta Gorda, Florida,](https://reader035.vdocument.in/reader035/viewer/2022062519/5697c0261a28abf838cd5f80/html5/thumbnails/22.jpg)
22
Concept of Intensive DMCA Management
![Page 23: Kwasi Badu-Tweneboah, Ph.D., P.E. – Geosyntec Consultants Jacksonville, Florida, USA Kenneth W. Cargill, P.E. – KW Cargill, P.A.. Punta Gorda, Florida,](https://reader035.vdocument.in/reader035/viewer/2022062519/5697c0261a28abf838cd5f80/html5/thumbnails/23.jpg)
Tracking Consolidationand Settlement
23
![Page 24: Kwasi Badu-Tweneboah, Ph.D., P.E. – Geosyntec Consultants Jacksonville, Florida, USA Kenneth W. Cargill, P.E. – KW Cargill, P.A.. Punta Gorda, Florida,](https://reader035.vdocument.in/reader035/viewer/2022062519/5697c0261a28abf838cd5f80/html5/thumbnails/24.jpg)
24
On-going Settlement in DMCA 2
![Page 25: Kwasi Badu-Tweneboah, Ph.D., P.E. – Geosyntec Consultants Jacksonville, Florida, USA Kenneth W. Cargill, P.E. – KW Cargill, P.A.. Punta Gorda, Florida,](https://reader035.vdocument.in/reader035/viewer/2022062519/5697c0261a28abf838cd5f80/html5/thumbnails/25.jpg)
Preliminary Construction Costs
• 3-yr contract for $5.9 million signed in 8/2011• Average cost of $120,000 per month to date• 29% of contract expended thru 9/2012• $500,000 per ft of settlement gained thru 9/2012• Key equipment used to date:
– 1 Swamp buggy– 2 Long-reach excavators– 1 dozer– 1 harrow/tractor
![Page 26: Kwasi Badu-Tweneboah, Ph.D., P.E. – Geosyntec Consultants Jacksonville, Florida, USA Kenneth W. Cargill, P.E. – KW Cargill, P.A.. Punta Gorda, Florida,](https://reader035.vdocument.in/reader035/viewer/2022062519/5697c0261a28abf838cd5f80/html5/thumbnails/26.jpg)
Summary• Dredging Permits for Ship Slip and Turning
Basin– Dredge anytime of year– No DO Limit and no fish windows
• Ability to dredge when needed– Continual negotiations with USACE and dredge
contractor– Permit and implement bed leveling concept
• Have disposal capacity in DMCAs thru 2050– Intensive DMCA management– Ocean disposal
26
![Page 27: Kwasi Badu-Tweneboah, Ph.D., P.E. – Geosyntec Consultants Jacksonville, Florida, USA Kenneth W. Cargill, P.E. – KW Cargill, P.A.. Punta Gorda, Florida,](https://reader035.vdocument.in/reader035/viewer/2022062519/5697c0261a28abf838cd5f80/html5/thumbnails/27.jpg)
Thank You
27