Jet_Probe_Sampling_Methodology.pdf

P.O. Box 68, McClellanville, SC 29458

(843) 887-3800 www.athenatechnologies.com, adam_freeze@athenatechnologies.com

May 3, 2013

Mr. Patrick Moore South Carolina State Ports Authority 176 Concord Street Charleston, SC 29401

RE: Subsurface Investigations, Wash Probes, Charleston Harbor Post 45 Project Entrance Channel and Extension, Charleston, South Carolina

Sampling Methodology and Project Discussion

Athena Technologies, Inc. (Athena) entered into a subcontract agreement with the South Carolina State Ports Authority (SCSPA) on February 20, 2013 to perform up to two-hundred and three (203) wash probes in the Charleston Harbor Entrance Channel, and proposed 3-mile extension, in support of the Charleston Harbor Post 45 Project. Field activities commenced on February 21, 2013 and concluded on April 18, 2013 with the completion of one-hundred and ninety-four (194) jet probes. The following is a discussion regarding the methodology utilized to complete the field sampling.

Prior to entering into a contract, Athena reviewed the offshore weather patterns and discussed the potential complications associated with offshore sampling during the months of February and March, with the SCSPA and US Army Corps of Engineers (USACE). Athena’s initial cost proposal, submitted on February 6, 2013, recommended the use of our thirty-five foot research vessel (RV) Artemis as the sampling platform for the project. Between the dates of February 21 to March 15, weather conditions were not favorable for offshore field work and resulted in the completion of only four wash probes. At this point, Athena determined that a larger vessel would be required to complete the project on schedule. A summary of offshore weather conditions from February 21 to April 18 is attached as Appendix A.

On March, 19th, Athena contracted the services of the fishing vessel (FV) Miss Georgia, based out of McClellanville, SC, to act as the primary sampling platform for the jet probe project. Miss Georgia has an overall length of sixty-eight feet. On April 7th, Athena contracted a second vessel, the FV Miss Sandra II, in order to ensure the project was completed on schedule. Miss Sandra II has an overall length of forty feet. The use of the larger fishing vessels allowed for safe jet probe operations offshore. Due to reduced mobility of the fishing vessels, a sampling radius of 50’ was established for the desired locations.

The research/fishing vessels navigated to the desired locations using a Trimble Ag132 differential global positioning system (DGPS), capable of sub-meter accuracy, interfaced with HYPACK software. The vessels would navigate to the desired location and were immobilized using a single anchor deployed from the bow. Once the vessel was immobilized, the coordinates at the site were verified against the desired coordinates to verify accuracy. Water depths were determined via lead line (at locations with low current velocities), length of jetting pipe and drill stem (at http://www.athenatechnologies.com/� locations with competent material at the seafloor), or by using fathometers when current velocities were too great or the material at the seafloor was too soft to obtain an accurate water depth using the jetting pipe.

Elevation data was recorded using a Trimble R8 Global Navigation Satellite System (GNSS) receiver (i.e., real-time kinematic (RTK) GPS). The R8 GNSS utilized the South Carolina Virtual Reference Station (VRS) as the base station. Elevation data was recorded in North American Vertical Datum of 1988 (NAVD88) and later converted to Mean Lower Low Water (MLLW) using the National Oceanic and Atmospheric Administration’s (NOAA) vertical datum transformation software VDatum (Version 3.2). Use of the R8 GNSS receiver was limited to the range of the cell towers associated with the VRS network. Athena utilized a signal amplifier in an attempt to increase the range of cell service. In general, cell coverage necessary for accurate elevation data was available up to fifteen miles offshore.

The jetting equipment consisted of a one and a half inch (1.5”) hollow steel probe, two inch (2”) drill stems, and a three inch (3”) flexible hose connected to the water pump onboard the vessel.

The pipe and hose were connected via reducers and camlock pipe fittings. The wash probe was lowered to the seafloor and a mechanical pump was turned on. During the probing process, the progress was monitored on deck using marked drill stem that allow for accurate measurements of the probe’s advancement. Once refusal was encountered, the antenna height of the R8 GNSS receiver was set as the length of tools below deck, and the receiver was placed on top of the drill stem. At this point, up to five measurements were recorded at each location in order to increase the confidence of the data. Upon completion of the data collection, the probe was retrieved using a mechanical winch.

Athena utilized two vessels in order to obtain elevation data from the sample locations positioned greater than fifteen miles offshore and well out of cell range. One vessel, within the range of the cell towers, would record tidal elevations at approximately thirty minute intervals and relay that tide information to the vessel completing the locations offshore. The offshore vessel would determine a water depth, via the steps outlined above, and would jet until refusal was encountered. Once refusal was met, the length of tools below the water line was determined and recorded. In order to determine the top of refusal elevation, the water level (i.e., tide elevation) would be subtracted from the length of tools below the water line. In some cases, refusal was not encountered, however the pipe penetrated well below the proposed project depth of minus fifty-eight feet MLLW.

Upon completion of the field work, the data was downloaded from the field computers and R8 GNSS receiver and consolidated to a central working spreadsheet. Field notes were compared with the stored data points to ensure accuracy. The elevation data, originally recorded in NAVD88, was then converted to MLLW using the VDatum software. Upon completion of the data report, a series of quality checks was performed to ensure accurate data. The final jet probe summary is attached as Appendix B.

APPENDIX A

SCSPA

Charleston Entrance Channel Jet Probes

Weather Summary February 21 - March 7, 2013

1293 Graham Farm Road, P.O. Box 68 McClellanville, SC 29458

(843) 887-3800 www.athenatechnologies.com

Date Predominant Wind Direction

Average Wind Speed (mph)

Average Wind Gust

(mph)

Average Wave Height (feet)

Dominant Wave Period

(seconds)

24-Hour Pressure Change (hPa)

Number of Jet Probes

Completed Field Observations/Marine Warnings/Advisories

2/21/13 NNE 8.4 11.5 2.2 8.0 1.5 1 11:00 - Depart site, taking waves over the bow while anchored, winds ~15-20 mph w/ higher gusts, seas ~4' at 6 second intervals

2/22/13 SE 21.1 25.3 6.2 6.5 -3.7 --

2/23/13 W 13.7 17.5 5.2 7.5 -4.5 --

2/24/13 NW 10.3 12.9 2.8 7.9 5.1 --

2/25/13 NE 18.7 22.7 4.8 7.6 -2.8 --

2/26/13 SSW 24.5 30.8 10.6 8.3 -8.0 -- Small Craft Advisory

2/27/13 W 23.2 28.5 6.3 6.8 4.3 -- Small Craft Advisory

2/28/13 W 25.4 31.0 6.2 6.0 1.6 -- Small Craft Advisory

3/1/13 WNW 13.0 17.2 2.9 5.1 1.9 --

3/2/13 WNW 19.7 24.8 3.5 4.7 -0.6 2 10:30 - Depart site, anchors are dragging, taking waves over the bow while anchored, winds ~20 mph w/ higher gusts, seas ~4 - 5' at 5 second intervals

3/3/13 WNW 18.6 23.5 4.0 5.5 4.0 --

3/4/13 W 17.3 22.5 3.9 5.1 4.6 --

3/5/13 SW 19.5 24.0 3.7 5.1 -13.6 -- Gale Warning/Small Craft Advisory

3/6/13 W - WNW 30.9 38.1 8.5 6.9 10.4 -- Gale Warning

3/7/13 N - NNW 17.5 23.3 4.9 8.3 5.1 --

Small Craft Advisory = Wind speeds of 25 to 38 mph

Notes The data presented above represents a summary of offshore conditions as reported by the following NOAA National Data Buoy Center weather buoy: Station 41004 (Edisto)

Gale Warning = Wind speeds of 39 to 54 mph

Total Number of Probes Completed =

Weather Summary March 8 - 17, 2013

1293 Graham Farm Road, P.O. Box 68 McClellanville, SC 29458

(843) 887-3800 www.athenatechnologies.com

Predominant Wind Direction

Average Wind Speed (mph)

Average Wind Gust

(mph)

Average Wave Height (feet)

Dominant Wave Period

(seconds)

24-Hour Pressure Change (hPa)

3/8/13 N winds 15 - 20 knots, seas 3 to 5 ft N 17.1 21.7 6.1 13.5 2.3 --

3/9/13 NE winds 10 - 15 knots, seas 3 to 5 ft NE 17.0 21.3 6.7 12.9 1.8 --

3/10/13 NE winds 10 - 15 knots, seas 3 to 5 ft NE 14.9 18.0 5.6 14.4 -1.5 --

3/11/13 SW winds 15 - 20 knots, seas 4 - 6 ft S - SE 16.2 20.3 5.1 13.5 -8.8 --

3/12/13 S winds 10 - 15 knots, seas 4 - 6 ft SW 21.6 26.2 8.6 7.5 -0.8 -- Small Craft Advisory

3/13/13 NW winds 15 - 20, gusts to 25 knots, seas 3 to 5 ft

NW 18.5 23.5 4.9 10.1 4.4 -- Small Craft Advisory

3/14/13 N winds 15 - 20, gusts to 25 knots, seas 3 to 4 ft NW 18.6 23.9 4.9 7.0 4.7 -- Small Craft Advisory

3/15/13 W winds 10 - 15 knots, seas 2 to 3 ft W 13.9 17.3 2.7 11.8 -5.5 1

10:00 - Depart site, anchors kept sliding at locations near the jetties, anchor slid during jet probing and broke the 1.5" jetting pipe, winds

~10 - 15 knots, seas approximately 2 - 3'

3/16/13 SW winds 15 - 20, gusts to 25 knots, seas 4 - 6 ft

SW 26.8 32.1 5.9 6.0 -2.7 -- Small Craft Advisory

3/17/13 SW winds 10 - 15, gusts to 20 knots, seas 4 - 5 ft

WSW - SW 22.1 26.3 4.3 5.4 2.5 -- Small Craft Advisory

4Total Number of Probes Completed, To Date =

Number of Probes Completed, This Period =

Notes Gale Warning = Wind speeds of 39 to 54 mph Small Craft Advisory = Wind speeds of 25 to 38 mph

* The data presented above represents a summary of offshore conditions as reported by the following NOAA National Data Buoy Center weather buoy: Station 41004 (Edisto) The Marine Forecast was derived from the National Weather Service in Charleston, SC, for the following Marine Zone: AMZ350 (Coastal waters from South Santee River to Edisto Beach, SC out 20 nautical miles).

Actual Offshore Conditions *

Marine ForecastDate Number of Jet

Probes Completed

Field Observations/Marine Warnings/Advisories

Weather Summary March 18 - 26, 2013

1293 Graham Farm Road, P.O. Box 68 McClellanville, SC 29458

(843) 887-3800 www.athenatechnologies.com

Predominant Wind Direction

Average Wind Speed (mph)

Average Wind Gust

(mph)

Average Wave Height (feet)

Dominant Wave Period

(seconds)

24-Hour Pressure Change (hPa)

3/18/13 NW winds 10 - 15 knots… becoming S 10 - 15 knots, seas 3 - 4 ft

Variable 10.5 13.3 3.2 6.9 -5.6 -- Outfitted the shrimp boat for jet probe operations

3/19/13 SW winds 10 - 15 knots, seas 2 - 3 ft W 12.0 14.9 3.0 6.6 3.4 2 Mobilized shrimp boat to the site from McClellanville. Started working around 2pm.

3/20/13 NE winds 15 - 20, gusts to 25 knots, seas 3 - 4 ft

NE 18.7 22.7 4.4 6.0 -4.8 -- Small Craft Advisory

3/21/13 NW winds 20 - 25 kt, becoming W 15 to 20 kn, seas 3 - 5 ft WNW 20.3 25.8 4.1 5.5 3.7 -- Small Craft Advisory

3/22/13 NE winds 15 - 20 knots… becoming SE 5 to 10 knots, seas 2 - 4 ft

NE 9.8 13.9 3.2 6.7 4.4 -- Repaired generator on shrimp boat

3/23/13 NE winds 15 - 20 knots, seas 2 - 4 ft ENE 14.1 17.3 2.9 6.9 -5.9 -- Repaired generator on shrimp boat

3/24/13 NE winds 15 - 20 knots… becoming W 15 - 20 kt, seas 5 - 7 ft

E shifting to NW 22.4 27.7 6.6 6.3 -8.4 -- Gale Warning

3/25/13 W winds 20 - 25 knots, gusts to 35 knots, seas

4 - 6 ft W 26.2 31.5 6.3 6.5 10.3 -- Gale Warning

3/26/13 W winds 15 - 20 knots with gusts to 25, seas 4 -

5 ft WNW 22.1 28.5 5.4 5.6 8.0 -- Small Craft Advisory

Field Observations/Marine Warnings/Advisories

Total Number of Probes Completed, To Date =

Notes

* The data presented above represents a summary of offshore conditions as reported by the following NOAA National Data Buoy Center weather buoy: Station 41004 (Edisto) The Marine Forecast was derived from the National Weather Service in Charleston, SC, for the following Marine Zone: AMZ350 (Coastal waters from South Santee River to Edisto Beach, SC out 20 nautical miles).

Gale Warning = Wind speeds of 39 to 54 mph Small Craft Advisory = Wind speeds of 25 to 38 mph

Number of Probes Completed, This Period =

Date Marine Forecast

Actual Offshore Conditions *

Number of Jet Probes

Weather Summary March 27 - April 4, 2013

1293 Graham Farm Road, P.O. Box 68 McClellanville, SC 29458

(843) 887-3800 www.athenatechnologies.com

Predominant Wind Direction

Average Wind Speed (mph)

Average Wind Gust

(mph)

Average Wave Height (feet)

Dominant Wave Period

(seconds)

24-Hour Pressure Change (hPa)

3/27/13 NW winds 15 knots, decreasing to 10 to 15 kt, seas 2 - 3 ft

NNW 15.3 20.5 3.7 8.0 2.0 10 Mobilized shrimp boat to the site from McClellanville. Started working around 11 am.

3/28/13 -- N 12.4 16.8 2.8 7.3 2.3 10

3/29/13 -- N to SSW 8.8 12.1 2.3 6.2 -0.3 6

3/30/13 -- SW 14.4 17.2 2.8 6.8 -4.9 --

3/31/13 -- SW 20.5 24.5 4.8 5.9 -5.8 -- Small Craft Advisory

4/1/13 -- SW to WSW 16.9 19.9 5.0 7.4 0.2 --

4/2/13 -- WSW to NE 15.0 18.0 3.9 6.8 5.9 3 Mobilized shrimp boat to the site from McClellanville - conditions too rough to work upon arrival. 18:00 - conditions safe to begin jet probing.

4/3/13 -- NE 16.3 19.3 4.0 6.8 2.6 3 09:00 - Depart site due to high winds/seas. Unfavorable extended forecast.

4/4/13 E winds 20 to 25 knots, with gusts to 30 kt, seas 5 to 8 ft

ENE 22.5 27.8 8.8 7.4 -11.1 -- Small Craft Advisory

Field Observations/Marine Warnings/Advisories

Total Number of Probes Completed, To Date =

Notes

* The data presented above represents a summary of offshore conditions as reported by the following NOAA National Data Buoy Center weather buoy: Station 41004 (Edisto) The Marine Forecast was derived from the National Weather Service in Charleston, SC, for the following Marine Zone: AMZ350 (Coastal waters from South Santee River to Edisto Beach, SC out 20 nautical miles).

Gale Warning = Wind speeds of 39 to 54 mph Small Craft Advisory = Wind speeds of 25 to 38 mph

Number of Probes Completed, This Period =

Date Marine Forecast

Actual Offshore Conditions *

Number of Jet Probes

Weather Summary April 5 - 18, 2013

1293 Graham Farm Road, P.O. Box 68 McClellanville, SC 29458

(843) 887-3800 www.athenatechnologies.com

Predominant Wind Direction

Average Wind Speed (mph)

Average Wind Gust

(mph)

Average Wave Height (feet)

Dominant Wave Period

(seconds)

24-Hour Pressure Change (hPa)

4/5/13 -- N 16.7 20.8 5.1 8.3 5.0 --

4/6/13 -- NNE 17.4 21.1 5.0 7.9 7.1 --

4/7/13 -- E 12.9 15.4 4.8 9.0 -1.0 20

4/8/13 -- E shifting to S 3.8 4.9 3.6 8.3 0.0 33

4/9/13 -- S to SW 5.3 6.4 3.3 9.0 0.6 21

4/10/13 -- SW to S 6.2 7.5 2.7 8.8 -4.2 15

4/11/13 -- S 11.7 13.1 4.1 6.4 -5.9 --

4/12/13 -- S to SW 18.4 21.8 6.6 7.5 -2.6 --

4/13/13 -- SW to E 11.3 13.9 3.9 7.5 7.3 6

4/14/13 -- E 11.8 14.1 3.9 6.7 -1.4 16

4/15/13 -- E to NNE 17.9 21.5 6.9 7.4 7.6 --

4/16/13 -- NNE 13.3 15.8 4.8 9.4 2.0 15

4/17/13 -- NE 11.2 13.0 4.0 8.5 -1.7 24

4/18/13 -- SE 13.4 16.0 4.1 7.7 -3.0 6

Number of Probes Completed, This Period =

Date Marine Forecast

Actual Offshore Conditions *

Number of Jet Probes

Completed Field Observations/Marine Warnings/Advisories

Total Number of Probes Completed, To Date =

Notes

* The data presented above represents a summary of offshore conditions as reported by the following NOAA National Data Buoy Center weather buoy: Station 41004 (Edisto) The Marine Forecast was derived from the National Weather Service in Charleston, SC, for the following Marine Zone: AMZ350 (Coastal waters from South Santee River to Edisto Beach, SC out 20 nautical miles).

Gale Warning = Wind speeds of 39 to 54 mph Small Craft Advisory = Wind speeds of 25 to 38 mph

APPENDIX B

February - April, 2013

1293 Graham Farm Road, P.O. Box 68 McClellanville, SC 29458

(843) 887-3800 www.athenatechnologies.com

ID Date Time East (x) North (y) Water Depth (feet) Water Elevation (feet relative to

MLLW)

Top of Refusal Elevation

(feet relative to

MLLW)

Notes

1 4/17/13 11:42:59 2370678.76 322514.12 49.2 4.1 -49.8

2 4/14/13 12:55:29 2370877.20 323018.45 55.5 3.9 -53.4

3 3/2/13 07:53:36 2372361.65 322212.88 51.7 3.6 -53.9

4 3/2/13 08:51:33 2372041.37 321849.80 47.4 4.7 -54.7

5 4/14/13 11:57:38 2373025.41 322129.28 51.7 4.5 -55.3

6 4/13/13 18:36:43 2369105.55 323965.82 53.1 2.6 -51.8

7 4/14/13 11:24:34 2372668.56 321571.54 51.8 4.9 -55.8

8 4/14/13 10:45:21 2372973.69 321359.57 51.5 5.0 -52.5

9 4/13/13 18:16:07 2370130.21 323824.56 51.6 2.3 -51.6

10 4/10/13 11:57:56 2375319.36 320317.55 52.6 1.3 -54.9

11 4/14/13 09:20:40 2373472.89 321173.00 52.6 4.6 -53.1

12 4/13/13 19:22:17 2374620.81 321379.45 45.8 3.6 -53.8

13 4/14/13 10:16:36 2374345.44 321377.24 52.2 5.0 -54.5

14 4/13/13 19:41:41 2374830.25 321145.18 50.3 4.1 -57.7

15 4/14/13 09:48:49 2373678.54 321384.71 57.4 4.8 -52.3

16 4/14/13 08:06:41 2374554.10 320523.62 50.6 3.5 -53.6

17 4/10/13 11:17:51 2375926.04 319732.48 51.7 2.2 -54.2

18 4/10/13 11:37:58 2375336.56 319895.90 43.6 1.8 -50.8

19 4/10/13 12:29:51 2375689.15 320377.52 52.4 0.5 -52.8

20 4/14/13 07:46:08 2375877.17 320495.92 51.3 3.2 -55.1

21 4/10/13 9:48:52 2378503.05 319145.34 52.8 4.6 -54.9

22 4/10/13 10:49:49 2376828.29 319590.17 55.8 2.8 -53.3

23 4/10/13 10:24:14 2377678.31 319655.52 50.6 3.7 -49.9

24 4/9/13 17:14:17 2377464.61 318866.65 48.5 3.8 -53.2

25 4/9/13 16:38:43 2378179.48 318506.55 48.0 2.9 -55.2

26 4/9/13 14:28:52 2379940.40 317537.64 52.5 -0.3 -54.7

27 4/10/13 8:31:14 2379734.06 318577.53 50.8 5.1 -50.7

28 4/10/13 7:53:18 2380290.54 318123.99 56.6 5.4 -53.9

29 4/9/13 14:50:26 2379517.02 317750.44 53.0 0.1 -54.1

30 4/9/13 13:25:11 2382137.36 316571.47 51.0 -0.4 -60.7 Jet pipe appeared to break through multiple thin layers of dense material prior to reaching final refusal depth.

31 4/9/13 13:01:09 2382256.82 316263.82 52.5 -0.3 -51.6

32 4/9/13 13:24:08 2382763.35 316890.97 48.1 -0.4 -48.4

33 4/9/13 13:50:05 2381701.36 316794.90 51.0 -0.3 -53.8

34 4/9/13 14:13:36 2380139.41 317732.77 51.0 -0.3 -51.7

35 4/14/13 10:39:03 2364958.65 326627.38 55.8 5.0 -51.7

36 4/13/13 19:43:20 2366731.90 325703.59 53.1 4.1 -50.2

February - April, 2013

1293 Graham Farm Road, P.O. Box 68 McClellanville, SC 29458

(843) 887-3800 www.athenatechnologies.com

ID Date Time East (x) North (y) Water Depth (feet) Water Elevation (feet relative to

MLLW)

Top of Refusal Elevation

(feet relative to

MLLW)

Notes

37 4/13/13 19:08:29 2368830.51 324537.45 50.8 3.3 -48.3

38 4/14/13 07:41:15 2367598.45 324340.15 53.7 3.1 -51.0

39 4/14/13 08:41:14 2365713.31 325333.81 54.1 3.9 -51.0

40 4/9/13 12:11:45 2385470.81 315142.86 52.0 0.1 -52.8

41 4/9/13 10:31:19 2385782.67 315275.06 40.8 2.5 -48.3

42 4/9/13 12:15:03 2385561.73 314367.99 56.2 0.0 -50.4

43 3/15/13 9:03:48 2382993.54 316022.32 53.6 4.1 -51.6 The anchor slid while jetting at second location of the day. Jetting pipe broke during slide.

44 4/9/13 12:42:08 2383492.06 316084.10 51.6 -0.3 -59.5

45 4/9/13 13:06:48 2382855.22 316428.99 51.6 -0.3 -54.8

46 4/9/13 8:43:02 2387230.61 314152.31 58.7 4.6 -52.2

47 4/9/13 11:43:06 2386770.20 313981.98 52.0 0.7 -51.7

48 4/8/13 13:46:06 2392176.07 310894.24 57.4 0.1 -56.0

49 4/8/13 12:47:16 2392701.92 310714.95 56.5 -0.3 -55.6

50 4/8/13 12:06:15 2394040.47 310454.78 55.9 -0.2 -54.4

51 4/8/13 11:19:53 2395740.50 309605.26 55.5 0.2 -54.4

52 4/8/13 10:24:02 2396167.46 309058.31 56.5 1.4 -54.3

53 4/8/13 11:44:28 2396625.52 309137.83 54.5 0.0 -53.4

54 4/8/13 9:45:52 2395720.80 308747.45 51.9 2.4 -50.8

55 4/3/13 8:35:56 2396968.45 308853.48 54.5 0.4 -56.1

56 4/3/13 8:19:03 2397052.52 308528.20 55.1 0.0 -53.3 Jet pipe broke through thin layer of dense material at ~ -51.9' MLLW.

57 4/3/13 8:00:11 2397884.42 308061.49 55.1 0.3 -54.1

58 4/2/13 19:36:21 2398853.13 307566.18 57.4 0.5 -54.2

59 4/2/13 18:34:40 2400176.23 307240.98 52.1 0.6 -52.7

60 4/2/13 18:08:25 2400074.03 306863.25 55.5 1.0 -54.3

61 3/29/13 11:48:52 2400093.63 306528.98 60.4 -- -54.3

62 3/29/13 11:26:36 2400959.67 306662.58 60.7 -- -51.8

63 3/29/13 10:45:52 2400884.56 306120.70 62.7 -- -56.8

64 3/29/13 11:05:50 2401136.44 306243.05 59.9 -- -52.5

65 3/29/13 9:49:24 2402175.93 305993.47 62.2 -- -57.4 Jet pipe appeared to break through multiple thin layers of dense material prior to reaching final refusal depth.

66 3/29/13 8:10:27 2401843.70 305887.18 61.5 -- -53.0

67 3/28/13 16:10:02 2401458.21 305815.28 57.8 -- -56.1

68 3/28/13 15:00:35 2402456.41 305849.19 54.7 -- -54.0

69 3/28/13 14:36:15 2402696.73 305419.92 56.1 -- -53.5

70 3/28/13 14:22:12 2402877.25 305038.58 55.3 -- -53.5

71 3/28/13 13:47:22 2403801.43 305249.22 55.8 -- -54.0

February - April, 2013

1293 Graham Farm Road, P.O. Box 68 McClellanville, SC 29458

(843) 887-3800 www.athenatechnologies.com

ID Date Time East (x) North (y) Water Depth (feet) Water Elevation (feet relative to

MLLW)

Top of Refusal Elevation

(feet relative to

MLLW)

Notes

72 3/28/13 13:34:58 2404042.79 304812.00 58.3 -- -53.6

73 3/28/13 13:10:15 2404158.33 304346.90 56.5 -- -53.6

74 3/28/13 12:53:10 2405341.95 304395.49 55.8 -- -57.1 Jet pipe appeared to break through multiple thin layers of dense material prior to reaching final refusal depth.

75 3/28/13 14:01:57 2403580.57 304469.26 56.5 -- -48.9

76 3/27/13 17:23:15 2406103.71 303521.91 60.1 -- -53.3

77 3/27/13 16:54:45 2406686.38 303506.27 61.7 -- -54.2

78 3/28/13 12:34:26 2405807.42 303370.58 59.9 -- -54.4

79 3/27/13 16:31:40 2407717.98 302853.53 55.8 -- -52.7

80 3/27/13 15:50:26 2408023.45 302410.44 54.8 -- -51.3

81 3/27/13 13:51:50 2409893.23 301557.18 54.0 -- -50.6

82 3/27/13 14:36:42 2409431.91 301814.01 55.1 -- -49.7

83 3/27/13 15:06:12 2408492.05 302359.96 56.7 -- -52.9

84 3/19/13 14:44:07 2410359.58 301295.65 58.0 -- -50.1

85 2/21/13 09:52:04 2410975.27 300727.50 49.4 -- -51.0 Bent anchor - we believe it was caught on exposed limestone.

86 3/27/13 11:09:50 2411863.23 300809.30 57.4 -- -51.8

87 3/27/13 12:25:03 2412054.81 300390.80 56.1 -- -53.1

88 3/27/13 13:03:36 2412409.86 300245.23 54.3 -- -50.3

89 4/7/13 15:46:29 2415048.62 298829.78 58.5 3.8 -54.0

90 4/7/13 15:03:56 2414523.98 299112.31 57.0 2.7 -51.7

91 4/7/13 15:23:15 2414313.93 298876.34 56.9 3.1 -52.7

92 4/7/13 14:35:25 2413839.52 299515.39 56.2 2.2 -51.2

93 4/7/13 14:10:58 2412962.32 300034.56 54.1 1.3 -50.8

94 4/10/13 8:16:30 2356544.21 330385.67 57.0 5.3 -53.0

95 4/10/13 7:38:13 2356789.78 331018.90 54.0 5.3 -55.8

96 4/10/13 8:40:03 2358430.31 330041.08 56.3 4.9 -55.6

97 4/10/13 8:55:13 2358662.38 329029.29 54.9 4.9 -50.5

98 4/9/13 8:09:28 2387596.76 313960.72 62.2 5.2 -53.3

99 4/8/13 16:49:00 2387866.99 313461.56 60.1 3.9 -57.0

100 4/8/13 15:48:59 2388882.85 312638.96 57.5 2.5 -55.7

101 4/8/13 14:30:06 2392010.76 311874.39 41.1 1.1 -50.5

102 4/8/13 14:59:27 2391313.47 312254.13 44.2 1.6 -50.0

103 4/8/13 14:05:37 2391025.35 311643.85 56.1 0.5 -56.1

104 4/8/13 15:25:10 2389264.04 313054.16 58.3 2.0 -51.6

105 4/10/13 9:44:04 2359691.64 328854.52 54.0 4.7 -50.1

106 4/10/13 10:33:16 2360013.71 329031.26 56.5 3.5 -53.6

107 4/14/13 12:15:04 2361816.88 328285.52 55.7 4.3 -53.9

February - April, 2013

1293 Graham Farm Road, P.O. Box 68 McClellanville, SC 29458

(843) 887-3800 www.athenatechnologies.com

ID Date Time East (x) North (y) Water Depth (feet) Water Elevation (feet relative to

MLLW)

Top of Refusal Elevation

(feet relative to

MLLW)

Notes

108 4/14/13 11:39:44 2361322.75 327635.40 54.1 4.8 -53.7

109 4/14/13 11:13:02 2363823.06 326677.27 55.2 4.9 -58.0 Jet pipe broke through multiple layers of dense material starting at ~ -53' MLLW.

110 4/14/13 10:57:23 2364258.45 326543.99 56.2 4.9 -60.2 Jet pipe broke through multiple layers of dense material starting at ~ -53' MLLW.

111 4/8/13 13:26:55 2422542.62 294231.22 52.4 -0.3 -63.4

112 4/8/13 13:01:51 2423032.56 294359.58 52.2 -0.4 -63.3

113 4/8/13 12:44:47 2423629.24 294472.66 51.7 -0.4 -64.4 Prior to reaching refusal depth, encountered dense material at ~ -63' MLLW.

114 4/8/13 11:30:28 2426825.96 292202.68 52.0 0.0 -61.8

115 4/8/13 11:47:40 2426469.29 292070.92 51.8 -0.2 -63.4

116 4/8/13 11:17:18 2427257.54 292357.95 51.3 0.1 -61.4

117 4/8/13 12:20:13 2425427.96 292960.56 51.6 -0.5 -62.3

118 4/8/13 10:58:00 2428193.41 291145.44 52.5 0.3 -66.2

119 4/8/13 10:46:04 2428618.35 291271.72 53.0 0.7 -66.3 No refusal encountered.

120 4/8/13 10:31:02 2429009.20 291401.86 52.3 1.1 -65.9 No refusal encountered.

121 4/8/13 14:31:55 2420194.85 295712.82 53.6 1.0 -58.9

122 4/9/13 9:00:21 2418857.17 296998.87 57.5 4.1 -57.1

123 4/9/13 8:40:40 2419335.50 296413.08 56.7 4.5 -54.4

124 4/8/13 14:12:25 2421671.89 295412.54 52.1 0.6 -61.9

125 4/8/13 13:58:58 2421425.53 295005.47 52.1 0.3 -63.8

126 4/8/13 13:43:32 2422118.49 294848.54 51.8 0.0 -57.8

127 4/9/13 9:48:00 2417541.35 296966.62 55.4 3.7 -54.2

128 4/7/13 16:29:51 2415442.44 298463.55 59.8 4.0 -57.2

129 3/19/13 18:12:17 2415692.18 298058.31 54.3 -- -55.7

130 4/7/13 18:17:45 2415985.85 298619.96 62.5 5.5 -54.7

131 4/9/13 10:10:56 2416793.61 298206.74 54.8 2.7 -56.0

132 4/8/13 10:04:03 2430800.21 289695.79 53.2 2.0 -65.0

133 4/8/13 9:50:06 2431347.64 289789.79 53.0 2.2 -64.8 No refusal encountered.

134 4/8/13 9:33:35 2432041.78 289797.46 53.7 2.6 -64.4 No refusal encountered.

135 4/8/13 9:12:27 2432709.49 288781.67 57.8 3.0 -67.0 No refusal encountered.

136 4/8/13 8:57:12 2432987.85 288830.96 58.8 3.3 -66.7 No refusal encountered.

137 4/8/13 8:12:32 2433514.50 288829.00 59.5 4.2 -65.8 No refusal encountered.

138 4/7/13 17:56:31 2435667.67 287541.87 56.1 5.2 -63.8 No refusal encountered.

139 4/7/13 18:28:12 2435373.30 287697.28 56.3 5.4 -64.6 No refusal encountered.

140 4/7/13 17:39:48 2435939.97 287445.58 46.8 4.9 -63.6 No refusal encountered.

141 4/7/13 17:13:38 2436228.05 287620.87 56.0 4.5 -62.0 No refusal encountered.

142 4/7/13 16:42:16 2437855.26 285745.71 57.0 4.1 -63.9 No refusal encountered.

February - April, 2013

1293 Graham Farm Road, P.O. Box 68 McClellanville, SC 29458

(843) 887-3800 www.athenatechnologies.com

ID Date Time East (x) North (y) Water Depth (feet) Water Elevation (feet relative to

MLLW)

Top of Refusal Elevation

(feet relative to

MLLW)

Notes

143 4/7/13 16:11:38 2439074.17 285532.48 55.2 3.8 -61.7 No refusal encountered.

144 4/7/13 15:49:14 2440327.64 285502.21 55.2 3.7 -61.3 No refusal encountered.

145 4/7/13 15:10:45 2441646.85 283819.87 56.3 2.8 -62.2 No refusal encountered.

146 4/7/13 14:50:12 2442753.74 283746.53 55.4 2.4 -62.6 No refusal encountered.

147 4/7/13 14:24:49 2442387.69 283386.08 54.5 1.7 -62.3 No refusal encountered.

148 4/7/13 13:55:31 2443010.87 283288.18 55.6 0.9 -63.1 No refusal encountered.

149 4/7/13 13:02:59 2443333.22 283745.52 52.9 -0.1 -63.1 No refusal encountered.

150 4/7/13 11:43:00 2447343.35 281580.52 54.2 0.0 -62.1

151 4/17/13 12:10:07 2370187.21 323034.65 54.2 4.4 -53.0

152 4/17/13 14:11:42 2372652.93 321688.48 53.8 4.2 -54.4

153 4/17/13 14:43:00 2373102.72 321884.48 53.9 3.9 -53.7

154 4/17/13 15:02:54 2373349.32 321520.86 56.2 3.8 -53.1

155 4/17/13 15:43:49 2374970.56 320620.91 55.7 3.2 -53.9

156 4/18/13 8:53:30 2376127.91 320120.35 54.2 1.5 -55.0

157 4/18/13 9:58:12 2375720.90 320089.11 53.6 2.6 -52.3

158 4/18/13 8:19:25 2376924.31 319175.67 49.5 1.4 -53.8

159 4/17/13 10:45:42 2378343.17 318738.93 56.6 3.6 -53.0

160 4/16/13 19:09:14 2382199.71 316943.98 57.7 1.7 -53.2

161 4/17/13 9:05:53 2379889.30 317855.62 57.4 2.1 -52.1

162 4/17/13 9:29:06 2381133.77 317257.60 57.2 2.5 -51.2

163 4/17/13 12:59:06 2366790.81 325190.22 60.4 4.5 -53.1

164 4/17/13 12:40:08 2368084.43 324515.99 58.3 4.5 -54.3

166 4/16/13 17:04:31 2386182.25 314726.46 57.7 1.7 -56.0

167 4/16/13 18:19:58 2384266.29 315993.52 52.8 1.4 -51.2

168 4/16/13 18:46:12 2383941.29 315839.18 57.5 1.5 -51.7

169 4/16/13 17:33:42 2386257.85 314109.39 57.8 1.4 -53.5

170 4/17/13 14:00:33 2394325.40 309642.92 55.0 4.2 -51.9 Prior to reaching refusal depth, encountered dense material at ~ -50.6' MLLW.

171 4/17/13 14:17:03 2394117.84 310158.77 55.3 4.0 -52.1

172 4/17/13 13:36:39 2395706.24 309122.64 55.5 4.4 -51.1

173 4/17/13 13:23:53 2396211.48 308510.28 50.7 4.4 -46.3

174 4/17/13 12:09:20 2403361.32 305181.50 55.0 4.2 -51.5

175 4/17/13 11:51:04 2404258.04 304099.98 52.5 4.1 -48.4

176 4/17/13 11:23:55 2407572.73 302602.64 52.8 3.8 -49.0

177 4/17/13 11:07:07 2408441.42 302126.91 53.0 3.7 -49.3

178 4/17/13 10:39:34 2411744.78 300488.78 53.3 3.5 -49.8 Video of sea floor/jetting process.

179 4/17/13 10:07:08 2412582.26 300331.67 52.0 3.0 -49.0

180 4/16/13 18:59:07 2414695.95 298541.88 52.3 1.5 -52.8

February - April, 2013

1293 Graham Farm Road, P.O. Box 68 McClellanville, SC 29458

(843) 887-3800 www.athenatechnologies.com

ID Date Time East (x) North (y) Water Depth (feet) Water Elevation (feet relative to

MLLW)

Top of Refusal Elevation

(feet relative to

MLLW)

Notes

181 4/17/13 9:25:06 2413501.94 299343.88 52.1 2.3 -50.2

186 4/18/13 8:36:07 2388035.03 314022.60 47.6 1.4 -48.9

187 4/18/13 8:01:13 2389010.17 312470.55 44.1 1.3 -45.5

188 4/17/13 15:14:52 2390988.52 312110.45 54.3 3.5 -52.6

189 4/17/13 14:45:06 2391760.39 311632.01 54.8 3.8 -52.2

191 4/18/13 11:00:05 2360158.65 329086.73 53.5 2.9 -54.3 Prior to reaching refusal depth, encountered dense material at ~ -52.7' MLLW.

195 4/16/13 16:39:40 2422693.91 294222.96 53.2 1.7 -60.4

196 4/16/13 16:22:44 2423375.98 294413.98 54.1 1.9 -59.4

197 4/16/13 15:54:04 2425350.56 292849.04 53.5 2.2 -62.8 No refusal encountered.

198 4/16/13 17:23:22 2420333.03 295935.80 53.5 1.4 -58.6

199 4/16/13 17:56:02 2419711.93 296479.27 52.4 1.3 -58.2

200 4/16/13 16:57:52 2422487.23 295059.06 53.0 1.6 -59.7

201 4/16/13 17:39:57 2419235.69 296044.72 54.1 1.3 -56.4

202 4/16/13 18:37:33 2416131.82 298037.89 52.2 1.2 -55.6

203 4/16/13 18:18:19 2417779.50 297399.23 53.4 1.2 -54.4

Project Notes

Coordinates were recorded in NAD83 South Carolina State Plane (Zone 3900), International Feet.

Due to time constraints, we did not perform jet probes at the following 2nd priority target locations: 165, 182-185, 190, and 192-194.

Elevations were recorded in NAVD88 in the field, and converted to MLLW using NOAA's VDatum Software (Version 3.2).

Water depths were determined via lead line (at locations with low current velocities), length of jetting pipe (at locations with competent material at the seafloor), or by using a fathometer when current velocities were too great, or the material at the seafloor was too soft to obtain an accurate water depth using the jetting pipe.

A Trimble R8 GNSS RTK unit was utilized to collect tidal elevations and top of refusal elevations. The R8 utilized the South Carolina Virtual Reference Station (VRS) network as the base station.