Daily Rules, Proposed Rules, and Notices of the Federal Government


National Oceanic and Atmospheric Administration

50 CFR Part 217

[Docket No. 110801452-2387-03]

RIN 0648-BB00

Taking and Importing Marine Mammals; Taking Marine Mammals Incidental to Construction and Operation of a Liquefied Natural Gas Deepwater Port in the Gulf of Mexico

AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and Atmospheric Administration (NOAA), Commerce.
ACTION: Proposed rule; request for comments.
SUMMARY: NMFS has received a request from Port Dolphin Energy LLC (Port Dolphin) for authorization to take marine mammals incidental to port construction and operations at its Port Dolphin Deepwater Port in the Gulf of Mexico, over the course of five years; approximately June 2013 through May 2018. Pursuant to the Marine Mammal Protection Act (MMPA), NMFS is proposing regulations to govern that take and requests information, suggestions, and comments on these proposed regulations.
DATES: Comments and information must be received no later than October 25, 2012.
ADDRESSES: *Electronic Submission:Submit all electronic public comments via the Federal e-Rulemaking submit comments via the e-Rulemaking Portal, first click the Submit a Comment icon, and then enter 110801452-2387-03 in the keyword search. Locate the document you wish to comment on from the resulting list and click on the Submit a Comment icon on the right of that line.

* Hand delivery or mailing of comments via paper or disc should be addressed to Michael Payne, Chief, Permits and Conservation Division, Office of Protected Resources, National Marine Fisheries Service, 1315 East-West Highway, Silver Spring, MD 20910.

Comments regarding any aspect of the collection of information requirement contained in this proposed rule should be sent to NMFS via one of the means provided here and to the Office of Information and Regulatory Affairs, NEOB-10202, Office of Management and Budget, Attn: Desk Office, Washington, DC 20503,

Instructions:Comments must be submitted by one of the above methods to ensure that the comments are received, documented, and considered by NMFS. Comments sent by any other method, to any other address or individual, or received after the end of the comment period, may not be considered. All comments received are a part of the public record and will generally be posted for public viewing onwww.regulations.govwithout change. All personal identifying information (e.g., name, address) submitted voluntarily by the sender will be publicly accessible. Do not submit confidential business information, or otherwise sensitive or protected information. NMFS will accept anonymous comments (enter N/A in the required fields if you wish to remain anonymous). Attachments to electronic comments will be accepted in Microsoft Word, Excel, or Adobe PDF file formats only.

FOR FURTHER INFORMATION CONTACT: Ben Laws, Office of Protected Resources, NMFS, (301) 427-8401.

A copy of Port Dolphin's application may be obtained by writing to the address specified above (seeADDRESSES), calling the contact listed above (seeFOR FURTHER INFORMATION CONTACT), or visiting the Internet at: help NMFS process and review comments more efficiently, please use only one method to submit comments.


Sections 101(a)(5)(A) and (D) of the MMPA (16 U.S.C. 1361et seq.) direct the Secretary of Commerce to allow, upon request, the incidental, but not intentional, taking of small numbers of marine mammals by U.S. citizens who engage in a specified activity (other than commercial fishing) within a specified geographical region if certain findings are made and either regulations are issued or, if the taking is limited to harassment, a notice of a proposed authorization is provided to the public for review.

Authorization for incidental takings shall be granted if NMFS finds that the taking will have a negligible impact on the species or stock(s), will not have an unmitigable adverse impact on the availability of the species or stock(s) for subsistence uses (where relevant), and if the permissible methods of taking and requirements pertaining to the mitigation, monitoring and reporting of such takings are set forth. NMFS has defined “negligible impact” in 50 CFR 216.103 as “* * * an impact resulting from the specified activity that cannot be reasonably expected to, and is not reasonably likely to, adversely affect the species or stock through effects on annual rates of recruitment or survival.”

Except with respect to certain activities not pertinent here, the MMPA defines “harassment” as: “any act of pursuit, torment, or annoyance which (i) has the potential to injure a marine mammal or marine mammal stock in the wild [`Level A harassment']; or (ii) has the potential to disturb a marine mammal or marine mammal stock in the wild by causing disruption of behavioral patterns, including, but not limited to, migration, breathing, nursing, breeding, feeding, or sheltering [`Level B harassment'].”

Summary of Request

On February 1, 2011, NMFS received a complete application from Port Dolphin for the taking of marine mammals incidental to port construction and operations at its Port Dolphin Deepwater Port (DWP) facility in the Gulf of Mexico (GOM). During the period of these proposed regulations (June 2013-May 2018), Port Dolphin proposes to construct the DWP and related infrastructure—expected to occur over an approximately 11-month period, beginning in June 2013—and to subsequently begin operations. The proposed DWP, which is designed to have an operational life expectancy of 25 years, would be an offshore liquefied natural gas (LNG) facility, located in the GOM approximately 45 km (28 mi) off the western coast of Florida, and approximately 68 km (42 mi) from Port Manatee, located in Manatee County, Florida, within Tampa Bay (see Figure S-1 in Port Dolphin's application). The DWP would be in waters of the U.S. Exclusive Economic Zone (EEZ) approximately 31 m (100 ft) in depth. The proposed DWP would consist principally of a permanently moored buoy system, designed for offloading of natural gas, leading to a single proposed new natural gas transmission pipeline that would come ashore at Port Manatee and connect to existing infrastructure.

Take of marine mammals would occur as a result of the introduction of sound into the marine environment during construction of the DWP and pipeline and during DWP operations, which would involve shuttle regasificationvessel (SRV) maneuvering, docking, and debarkation, as well as regasification activity. Because the specified activities have the potential to take marine mammals present within the action area, Port Dolphin requests authorization to incidentally take, by Level B harassment only, small numbers of bottlenose dolphin (Tursiops truncatus) and Atlantic spotted dolphin (Stenella frontalis).

Description of the Specified Activity

Port Dolphin proposes to own, construct, and operate a DWP in the U.S. EEZ of the GOM Outer Continental Shelf (OCS) approximately 45 km (28 mi) off the western coast of Florida to the southwest of Tampa Bay, in a water depth of approximately 31 m (100 ft). On March 29, 2007, Port Dolphin submitted an application to the U.S. Coast Guard (USCG) and the U.S. Maritime Administration (MarAd) for all federal authorizations required for a DWP license under the Deepwater Port Act of 1974 (DWPA). Port Dolphin received that license in October 2009. The Port would consist of a permanently moored unloading buoy system with two submersible buoys separated by a distance of approximately 5 km (3 mi). The buoys would be designed to moor a specialized type of LNG carrier vessel (i.e., SRVs) and would remain submerged when vessels are not present. Regasified natural gas would be sent out through the unloading buoy to a 36-in (0.9 m) pipeline that would connect onshore at Port Manatee with the existing Gulfstream Natural Gas System and Tampa Electric Company (TECO) Bayside pipeline. The DWP would only serve SRVs. Construction of the DWP would be expected to take 11 months. Port Dolphin DWP would be designed, constructed, and operated in accordance with applicable codes and standards and would have an expected operating life of approximately 25 years. The locations of the DWP and associated pipeline are shown in Figure S-1 in Port Dolphin's application; Figure 1-1 of the same document depicts a conceptual site plan for the DWP.

The installation of the DWP facilities would include the construction and installation of offshore buoys, mooring lines, and anchors. The two unloading buoys, also known as submerged turret loading (STL) buoys, would each have eight mooring lines connected to anchor points, likely consisting of piles driven into the seabed. When not connected to a SRV, STL buoys would be submerged 60 to 70 ft (18 to 21 m) below the sea surface. The installation of the pipeline from the DWP to shore would include burial of the pipeline, selective placement of protective cover (either rock armoring or concrete mattresses) over the pipeline at several locations along the pipeline route where full burial is not possible, and the horizontal directional drilling (HDD) of three segments of the pipeline.

SRVs are specialized LNG carriers designed to regasify the LNG prior to off-loading for transport to shore. Each STL buoy would moor one SRV on location throughout the unloading cycle. An SRV would typically moor at the deepwater port for between 4 and 8 days, depending on vessel size and send-out rate. Unloading of natural gas (i.e., vaporization or regasification) would occur through a flexible riser connected to the STL buoy and into the pipeline end manifold (PLEM) for transportation to shore via the subsea pipeline. With two separate STL buoys, Port Dolphin may schedule an overlap between arriving and departing SRVs, thus allowing natural gas to be delivered in a continuous flow.

Port Dolphin is planning for an initial natural gas throughput of 400 million standard cubic feet per day (MMscfd). Although the Port would be capable of an average of 800 MMscfd with a peak capacity of 1,200 MMscfd, this level of throughput would not be achieved during the span of this proposed rule. Based on a regasification cycle of approximately 8 days and initial throughput of 400 MMscfd, maximum vessel traffic during operations over the lifetime of the proposed 5-year regulations is projected to consist of 46 SRV unloadings per year.

In the open ocean, SRVs typically travel at speeds of up to 19.5 kn (36.1 km/hr). When approaching the vicinity of the DWP (i.e., during approach to the DWP), the SRVs would typically slow to about half speed. In close proximity to the STL buoys, the SRVs would slow to dead slow and utilize thrusters to attain proper vessel orientation relative to the DWP, taking into consideration ambient ocean currents, wind conditions, and buoy position. The following subsections describe the Region of Activity and the preceding facets of construction and operation in greater detail.

Region of Activity

The GOM is a marine water body bounded by Cuba on the southeast; Mexico on the south and southwest; and the U.S. Gulf Coast on the west, north, and east. The GOM has a total area of 564,000 km2(217,762 mi2). Shallow and intertidal areas (water depths of less than 20 m) compose 38 percent of the total area, with continental shelf (22 percent), continental slope(20 percent), and abyssal plain (20 percent) composing the remainder of the basin. The project site is located on the west Florida Shelf, a portion of the Inner Continental Shelf, in an area of relatively low wave energy and tidal variation (Gore, 1992).

The GOM is separated from the Caribbean Sea and Atlantic Ocean by Cuba and other islands, and has relatively narrow connections to the Caribbean and Atlantic through the Florida and Yucatan Straits. The GOM is composed of three distinct water masses, including the North and South Atlantic Surface Water (less than 100 m deep), Atlantic and Caribbean Subtropical Water (up to 500 m deep), and Subantarctic Intermediate Water.

Circulation within the GOM, and within the project area, is dominated by the Loop Current, which enters the GOM flowing north through the Yucatan Strait, flows south along the Florida coast in the vicinity of the project area, and exits the GOM through the Florida Straits. The velocity of the current in the project area ranges between 1.56 and 15.16 cm/s in summer, and 1.79 to 25.36 cm/s in winter (APL, 2006). The direction of flow in the project area is generally south to southeast.

In shallow areas along the west Florida Shelf, additional influences on water flow and circulation include wind stress, freshwater inflow, and variations in buoyancy (Gore, 1992). Wind speeds at the project site range from 2.26 to 7.61 m/s in summer, and 2.85 to 11.04 m/s in winter (APL, 2006). Tidal variation along Florida's west-central continental shelf is moderate, with an average range of approximately 2 ft (0.6 m) (Gore, 1992).

At the eastern edge of the Loop Current along the west Florida Shelf, circulation patterns result in an upwelling of deep nutrient-rich water. This upwelling supports a high level of biological activity, producing large concentrations of plankton. Nutrient levels (primarily nitrogen and phosphorus) are also affected by runoff from agricultural and urbanized areas and from submarine groundwater discharge, leading to red tide conditions. In the project area, red tide occurs on an almost annual basis (Huet al.,2006). Red tides are caused by rapid growth of the speciesKarenia brevis,a toxic species which produces brevetoxins (a type of neurotoxin) that can accumulate in bivalves and cause mortality in marine organisms (Huet al.,2006). The rapid growth of these organisms can also create a hypoxic zone (area with dissolved oxygenconcentrations below 2 mg/L), which can cause mortality among benthic communities, fish, turtles, birds, and marine mammals (Huet al.,2006).

Extreme variations in water circulation patterns, tides, and wave heights can occur along the west Florida coast during periodic tropical storms and hurricanes. Warm water within the Loop Current can act as an energy source in summer and fall months, fueling the development of these storms. Features of these storms that can affect natural circulation and topography include high winds, flooding, storm surges, and beach erosion.

Tampa Bay is an estuary formed by the rise of sea level into a former river valley. Tampa Bay consists of four subregions, including lower Tampa Bay, middle Tampa Bay, Old Tampa Bay, and Hillsborough Bay. The project area would only extend to Port Manatee, within Lower Tampa Bay, near the outlet of the bay into the GOM. The bay covers an area of 1,030 km2within Hillsborough, Manatee, and Pinellas counties. Freshwater inflow to the bay occurs through four major river systems (Alafia, Hillsborough, Little Manatee, and Manatee), as well as more than a hundred minor creeks and rivers.

Water circulation within the bay is driven by freshwater inflow, tides, and winds. The bay has an average depth of 3.5 to 4 m. There is well-developed horizontal stratification in the bay, with fresh water flowing along the surface out to sea, and denser saline water flowing into the bay along the bottom.

The Tampa Bay area has a population of more than two million people, and tributaries, habitat, runoff patterns, and water quality are all affected by urbanization. Specific actions that have affected the bay include removal of mangroves, dumping of sewage, artificial filling, and modification of runoff from paved surfaces (Peeneet al.,1992).

Dates of Activity

Port Dolphin has requested regulations governing the incidental take of marine mammals for the five-year period from June 2013 through May 2018. Construction and installation of the port and pipeline would last approximately 11 months, with subsequent operations (i.e., SRV docking and regasification) occurring for the remainder of the specified time period.

LNG and SRVs

The DWPA establishes a licensing system for ownership, construction, and operation of deepwater ports in waters beyond the territorial limits of the United States. Originally, the DWPA promoted the construction and operation of deepwater ports as a safe and effective means of importing oil into the United States and transporting oil from the OCS, while minimizing tanker traffic and associated risks close to shore. The Maritime Transportation Security Act of 2002 amended the definition of “deepwater port” to include facilities for the importation of natural gas.

LNG is natural gas that has been cooled to about −260 °F (−162 °C) for efficient shipment and storage as a liquid. LNG is more compact than the gaseous equivalent, with a volumetric differential of about 610 to 1. LNG can thus be transported long distances across oceans using specially designed ships (e.g., SRVs), allowing efficient access to stranded reserves of natural gas that cannot be transported by conventional pipelines.

This proposed STL buoy system differs from other common LNG offload technologies insofar as it does not involve any permanent storage or regasification facility at the DWP, thus minimizing required infrastructure at the DWP itself. Rather, STL buoys receive SRVs that contain onboard LNG vaporization equipment. After mooring, LNG is vaporized onboard the vessel and discharged via the unloading buoy and a flexible riser into the subsea pipeline. Because the LNG is vaporized with the SRV's onboard equipment, no permanent fixed or floating storage or vaporization facilities are required. However, this means that the offload process can take 5 to 8 days, as compared with a standard offload of 18 hours or less. As a result of this trade-off, continuous off-loading operations are essential to minimize fluctuations in the throughput of natural gas. The SRVs proposed for use would be equipped to transport, store, vaporize, and meter natural gas. A closed-loop, glycol/water-brine heat transfer system would be used to vaporize the LNG. Closed-loop systems burn vaporized LNG in order to heat an intermediate fluid (e.g., glycol/water-brine), which warms the LNG. The closed-loop system results in reduced environmental impacts on water quality and marine resources; although these systems do require seawater for use in cooling electrical generating equipment (resulting in subsequent entrainment of fish eggs and plankton, as well as discharge of water at elevated temperatures), such usage is significantly reduced from that required in an open-loop system.

SRVs with approximate cargo capacities of either 145,000 m3or 217,000 m3(189,653-283,825 yd3) based on standard designs for oceangoing LNG carriers would be used to supply LNG to the Port. Approximate dimensions of each SRV would range from 280 m (919 ft) in length and 43 m (141 ft) in breadth, with a design draft of 11.4 m (37.4 ft) for the smaller vessels to 315.5 m (1,035 ft) in length and 50 m (164 ft) in breadth, with a design draft of 12 m (39 ft) for the larger vessels. The maximum height above the waterline would be 41.1 m (135 ft). The 145,000 m3SRV would displace 80,000 t (88,185 ton) and the 217,000 m3SRV would displace 108,000 t (119,050 ton). The vessels would be equipped with a trunk and mating cone to receive the unloading buoy, lifting and connection devices, an LNG vaporization system, and gas metering systems. All critical functions would be manned 24 hours per day; other functions would be accomplished on a regular, scheduled basis.

The SRVs would have two thrusters forward and could have one or two thrusters aft. Thrusters allow precise control of positioning while mooring with the STL buoy. The dynamic positioning system would be used while retrieving the submerged unloading buoy handling line and moving onto the buoy. The system normally would not be used while the SRV is moored to the unloading buoy. SRVs would be equipped with an acoustic position reporting system that would monitor the buoy's draft and position before and during connection/disconnection; this would be enabled by six transponders located on the buoy itself.

Seawater would be used to ballast the SRV, cool the dual-fuel diesel engines supplying power for the regasification process, and condense the steam produced by the boilers supplying heat to the vaporization process. Ballasting the SRV is required to maintain proper buoyancy as the LNG is vaporized and offloaded through the pipeline. Water intake for ballasting the SRV would require an average intake of 360 m3per hour (2.3 MGD) over the vaporization cycle. The cooling water system would require an additional intake of approximately 1,520 m3per hour (9.5 MGD) and would take in seawater through one of two sea chests, each measuring 1.5 x 2.0 m (4.9 x 6.6 ft). Water velocity through the lattice screens at the hull side shell would not exceed 0.15 m/s (0.49 ft/s) at the maximum flow rate of 1,520 m3per hour.

Cooling water discharges would be made at points removed from the intake sea chests to avoid recirculating warmed water through the cooling system. All of the cooling water would be dischargedat a temperature of approximately 10 °C (18 °F) above the ambient water temperature. Although the seawater system would be equipped with a chlorination system to prevent biofouling of heat transfer surfaces and system components, the chlorination system would not be used while the SRVs are approaching the Port or moored at the buoys.

Port Construction

In-water construction of Port Dolphin is expected to begin in June 2013 and last a total of approximately 11 months. Construction would include siting the STL buoys and associated equipment and laying the marine pipeline. Construction is assumed to be continuous from mobilization to demobilization with no work stoppages due to weather or other issues. Please see Table 2-1 of Port Dolphin's application for a graphical depiction of the complete timeline of proposed construction activities. Port Dolphin anticipates that construction/installation would be accomplished in the following sequence:

• Install the Port Manatee HDD section, with installation proceeding from onshore to the offshore location.

• Install the anchor piles and the mooring lines using the main installation vessel at the DWP.

• Construction and installation of the HDD pipe sections for the segments under the existing Gulfstream pipeline.

• Install seabed pipe segments between the Port Manatee HDD segment and the Gulfstream HDD segments.

• Install the Skyway Bridge section of the pipe (requiring dredging through the causeway).

• Install the STL Buoys.

• Install the two risers from the PLEMs.

• Install the north and south PLEMs.

• Perform pipelay and diving operations towards the Y-connector.

• Install the flowlines on the seafloor.

• Complete tie-ins and bury or armor the pipeline, as necessary.

• Conduct testing of the pipeline upon completion of burial operations.

These components of in-water construction are discussed in greater detail in the following subsections.

DWP Construction/Installation—As described previously, the Port would include two STL unloading buoy systems, separated by a distance of approximately 5 km (3.1 mi) in a water depth of approximately 31 m (100 ft). Each unloading buoy would have eight mooring lines, consisting of wire rope and chain, connecting to eight driven-pile anchor points on the sea floor, one 16-in (0.4-m) inside diameter flexible pipe riser, and one electrohydraulic control umbilical from the unloading buoy to the riser manifold. When not connected to a SRV, STL buoys would be submerged 60 to 70 ft (18 to 21 m) below the sea surface. A concrete or steel landing pad would be fixed to the sea floor by means of a skirted mud mat to allow lowering of the STL buoy to the ocean floor when it is not in use.

The mooring lines would be designed so that the SRV could remain moored in non-hurricane 100-year storm conditions, and would vary in length, from 1,800 to 4,000 ft (549 to 1,219 m) for the northern unloading buoy and from 2,500 to 3,600 ft (762 to 1,097 m) for the southern buoy. The mooring lines would consist of 132-mm (5.2-in) chain and 120-mm (4.7-in) spiral-strand wire rope. The riser system for each unloading buoy would consist of one 16-in interior diameter flexible riser in a steep-wave configuration. Total length of the riser would be approximately 82 m (269 ft). The riser would be directed between two of the mooring lines, and would lie on the seafloor when not in use.

The two PLEMs near the unloading buoys would connect the flexible risers to the flowlines and a Y-connection that would connect the two flowlines to the new gas transmission pipeline. Each of the two PLEMs would be approximately 75 m (246 ft) offset from the proposed unloading buoy locations. The purpose of a PLEM is to provide an interface between the pipeline system and the flexible riser, isolate the riser between gas unloading operations, and attach a subsea pig launcher or receiver as necessary. “Pigs,” or “pipeline inspection gauges,” travel remotely through a pipeline to conduct inspections of or clean the pipeline and collect data about conditions in the pipeline. Each PLEM would include a flange connection for attaching the flexible riser or the subsea pig launcher/receiver and a full-bore subsea hydraulic control valve and electrohydraulic umbilical termination assembly. Each PLEM would have a mud mat foundation to provide a stable base for bearing PLEM and riser weight and to resist sliding and overturning forces. Please see Figure 1-1 in Port Dolphin's application for a conceptual diagram of the DWP.

Offshore installation activities at the DWP would begin with installation of the PLEMs at both STL buoy locations (north and south), followed by placement of the buoy anchors, mooring lines, buoys, and risers. Installation activities at both STL buoy locations would require a cargo barge, supported by anchor-handling support vessels, a supply boat, a crew transfer boat, and a tug. Buoy anchors would likely be installed via impact pile driving.

Pipeline Installation—The pipeline would be laid on the seafloor by a pipelaying barge and then buried, typically using a plowing technique. Other techniques, such as dredging and HDD, are planned to be used in certain areas depending on the final geotechnical survey, engineering considerations, and equipment selection. At the western (seaward) end, the pipeline would consist of two 36-in (0.9-m) flowlines connected to the north and south PLEMs, which would connect at a Y-connection approximately 3.2 km (2 mi) away (see Figure 1-1 in Port Dolphin's application). From the Y-connection a 36-in (0.9-m) gas transmission line would travel approximately 74 km (46 mi) to interconnections with the Gulfstream and TECO pipeline systems. The pipelines would have a nominal outer diameter of 36 in, with a coating of fusion-bonded epoxy and a concrete weight coating thickness of 11.4 cm (4.5 in).

Pipeline trenching and burial requirements are governed by Department of the Interior regulations at 30 CFR 250 Subpart J, which requires pipelines and all related appurtenances to be protected by 3 ft (0.9 m) of cover for all portions in water depths less than 200 ft (61 m). Portions of the pipeline that travel through hard-bottom areas may not be able to be buried to the full 3 ft depth. In these areas, flexible concrete mattresses or other cover would be used to cover the pipeline. In places where the pipeline crosses shipping lanes, it would be buried 10 ft (3 m) deep if the sea floor permits plowing. Burying the pipeline and flowlines would protect them from potential damage from anchors and trawls and avoid potential fouling, loss, or damage of fishermen's trawls. The pipeline construction corridor would be 3,000 ft (914 m) wide in offshore areas. The permanent in-water right-of-way for the pipeline would be 200 ft (61 m) wide.

Under the plowing method, the pipeline is lowered below seabed level by shearing a V-shaped ditch underneath it. The plow is towed along and underneath the pipeline by the burial barge. As the ditch is cut, sediment is removed and passively pushed to the side by specially shaped moldboards that are fitted to the main plowshare. The trench is then backfilled with a subsequent pass of the plow. The estimated width of the trench (including sediments initially pushed to each side) is 67 ft (20.4 m) (see Figure 1-2 in PortDolphin's application for a conceptual diagram of this process).

In areas that cannot be plowed (e.g., due to hard/live bottom) or complete burial cannot be achieved, the pipeline would be covered with an external cover (e.g., concrete mattresses or rock armoring). Although plowing is the preferred methodology for pipeline burial, other techniques such as dredging and HDD would be used where required. Figure 1-3 of Port Dolphin's application uses color coding of the proposed pipeline route to show where these various methodologies would be used, based on bottom structure and other barriers. The total length of the pipeline route is 74 km. Burial techniques to be used along the pipeline route and their relative lengths are characterized as follows:

• Plowing/trenching soft sediments: 39.6 km (24.6 mi; 53.2 percent of total pipeline length);

• Plowing/external cover: 23.3 km (14.5 mi; 31.4 percent);

• External cover (concrete mattress/rock armoring): 8.5 km (5.3 mi; 11.7 percent);

• Clamshell dredging/dragline burial: 0.3 km (0.2 mi; 0.5 percent); and

• HDD: 2.4 km (1.5 mi; 3.2 percent).

HDD would be employed for installation of the pipeline at three locations along the inshore portion of the route. The proposed HDD locations include drilling from land to water at the Port Manatee shore approach and from water-to-water at two crossings of the existing Gulfstream pipeline. The eastern HDD crossing would be 898 m (2,947 ft) in length, and the western HDD crossing would be 407 m (1,335 ft) in length. Both crossings would be in a water depth of 6.4 m (21 ft). The Port Dolphin pipeline would be drilled to a depth of approximately 6 m (20 ft) below the existing Gulfstream Pipeline (Port Dolphin, 2007b).

HDD is a steerable method of installing pipelines underground along a prescribed bore path, with minimal impact on the surrounding area. The process starts with location of entry and exit points. The first stage drills a pilot hole on the designed path, and the second stage enlarges the hole by passing a larger cutting tool known as a reamer. This would involve using progressively larger drill strings to eventually produce a drill bore 48 in (1.22 m) in diameter. The third stage places the product or casing pipe in the enlarged hole by way of the drill steel and is pulled behind the reamer to allow centering of the pipe in the newly reamed path. Simultaneously, bucket dredging would be employed to produce an exit hole at the end of the bore. In-water HDD may involve significant distance between the seabed and the drilling rig, and so a casing pipe may be required during the initial pilot hole drilling to provide some rigidity to the drill pipe as it is pushed ahead by the rig. Structures known as “goal posts” provide support for the casing pipe and are typically comprised of two driven piles with cross members set at predetermined elevations.

Port Dolphin has identified the need to install goal posts as part of the HDD drilling effort at the two water-to-water HDD locations. One potential option is that the goal posts are designed to self-install; however, another option is that drilling may be required. Further, at the shore-to-water transition HDD, Port Dolphin would need to install sheet piling to form a coffer dam, designed to contain the HDD exit pit so as to not impact nearby aquatic vegetation. Sheet pile segments would be installed by vibratory means.

Clam shell dredging would be required for passage under the Skyway Bridge and would be performed from a fixed working platform. Although dredging, followed by conventional lay and bury, is the most likely scenario, HDD remains a possibility for this segment. In the area near Manbirtee Key, a flotation ditch—dredging operations may require such a ditch when the minimum water depth necessary to safely float equipment is not present—would be dredged using conventional dredging equipment (i.e., the same barge that would be used to pull-in the shore approach HDD). The anticipated locations where the various methods of pipeline installation would be used are shown in Figure 1-3 of Port Dolphin's application.

There are eleven locations where tie-in operations would be required to piece the pipeline sections together. This mechanical operation is accomplished with specially designed connectors and a manned diving rig. This common operation does not require welding. Tie-ins would be required at each end of all HDD crossings, the Y-connection, and the PLEMs.

Construction Vessels—A shallow-water lay barge, spud barge and clamshell dredge, and a jack-up barge would be mobilized for offshore pipe-laying activities. Jack-up barges are mobile work platforms that are fitted with long support legs that can be raised or lowered; upon arrival at the work location the legs would be lowered and the barge itself raised above the water such that wave, tidal and current loading acts only on the relatively slender legs and not on the barge hull. A spud barge is a type of jack-up barge that typically offers increased stability but does not raise the hull above the water. This equipment would be used where conventional installation methods are anticipated. An HDD spread, including four jack-up barges, three hopper barges (designed to carry materials), and two tugs for barge towing, would be used for the three planned HDD segments. Four diving support vessels would also support tie-in and mattressing operations. Construction equipment would make one round-trip to the project location, staying on location for the duration of construction activity. Work crew vessels and supply vessels would make on average two trips a day for the duration of offshore construction. Work crew and supply vessels are expected to make between 420 and 450 round-trips to the offshore construction location from shore-based facilities for the duration of the project.

Table 1 details the vessels that would be used during the DWP and pipeline construction and installation activities. The projected duration and duty load of each vessel are also provided. Duty load is a primary consideration when characterizing project-related sound sources.

Table 1—Vessels To Be Employed During Port Dolphin Construction and/or Facility Installation Operations Operation Auxiliary equipment/notes Engine specifications1 Operational usage2 Construction/Installation at DWP Barge N/A 3.5 months at 100%. Anchor-handling support vessels ROV winches, hydraulic pumps, thrusters, sonar, survey equipment 2 × 3,750-hp Supply boat Bow thruster 671-hp Crew transfer boat 671-hp Tug 800-hp Impact hammer N/A As required. Pipelineinstallation Jack-up: Port Manatee HDD Jack-up 3,000-hp 27 days at 50%. Spud lay barge: Shallow lay operation; no propulsion; uses two tugs Tug 1,200-hp 59.4 days at 75%. Tug 1,200-hp East jack-ups Jack-up 3,000-hp 27 days at 75%. Jack-up 3,000-hp West jack-ups Jack-up 3,000-hp 27 days at 75%. Jack-up 3,000-hp Pipelay barge: Large lay barge operation; no propulsion; uses two tugs Tug 2,000-hp 37 days at 85%. Tug 2,000-hp Dragline barge 600-hp 6 days at 100%. Plow lay barge: Plow burial operation; no propulsion; uses two tugs Tug 2,000-hp 113 days at 85%. Tug 2,000-hp DSVs for mattress armoring Vessel 1,000-hp 108 days at 100%. Vessel 1,000-hp DSVs for mattress armoring Vessel 1,000-hp 12 days at 15%. 1,000-hp Vessel 1,000-hp 1,000-hp Pipeline gauge, fill, test, dewater, and drying Vessel 300-hp 13 days at 35%. 300-hp Vessel 300-hp 300-hp Survey vessel Vessel 1,000-hp 54 days at 50%. Vessel 1,000-hp Spud lay barge: Shallow lay barge operation; no propulsion; uses two tugs Tug 1,200-hp 6.6 days at 15%. Tug 1,200-hp East jack-ups Jack-up 2,000-hp 3 days at 15%. Jack-up 2,000-hp West jack-ups Jack-up 2,000-hp 3 days at 15%. Jack-up 2,000-hp Pipelay barge: Large lay barge operation; no propulsion; uses two tugs Tug 2,000-hp 4 days at 15%. Tug 2,000-hp Dragline barge Barge 600-hp 1 day at 15%. Plow lay barge: Plow burial operation; no propulsion; uses two tugs Tug 2,000-hp 13 days at 15%. Tug 2,000-hp DSVs for mattress armoring Vessel 1,000-hp 12 days at 15%. 1,000-hp Vessel 1,000-hp 1,000-hp Pipeline gauge, fill, test, dewater, and drying Vessel 300-hp 1 day at 15%. 300-hp Vessel 300-hp 300-hp Survey vessel Vessel 1,000-hp 6 days at 15%. HDD operations Jack-up: Port Manatee HDD Jack-up 3,000-hp 3 days at 15%. Spud barge Crane-mounted drill and vibratory drill; ancillary equipment includes welding equipment, air compressor, and generator N/A Maximum 4 days for vibratory drilling at each HDD location. Tug 800-hp Maximum 4 days for vibratory drilling at each HDD location. DSV = Diving spread vessels 1All specifications are for diesel engines. 2All figures assume 24 hrs/day; percentages refer to percent maximum duty load. Port Operations

The proposed DWP operations would include SRV maneuvering/docking, regasification of LNG cargo, and debarkation. The SRVs are expected to approach the DWP from the south. In the open ocean, the SRVs typically travel at speeds of up to 19.5 kn (36.1 km/hr), reducing to less than 14 kn (25.9 km/hr) while maintaining full maneuvering speed. However, once approaching the vicinity of the DWP—within approximately 16 to 25 km (10-16 mi) of the DWP—the SRVs would begin approach by slowing to about half speed, and then to slow ahead. Inside of 5 km (3.1 km) from the DWP, the SRVs' main engines would be placed in dead slow ahead and decreased upon approach to dead slow, with final positioning and docking to occur using thrusters. Expected SRV transit, approach, and maneuvering/docking characteristics are outlined in Table 2. Only the maneuvering/docking activities and their associated sound sources (i.e., thrusters) are considered in this document; transit and approach maneuvers are considered part of routine vessel transit and are not considered further.

Table 2—SRV Speeds and Thruster Use During Transit, Approach, and Maneuvering/Docking Operations at the DWP Zone Speed limit Thrusters in use? >33 km from DWP Full service speed (19.5 kn) No 25-33 km from DWP Full maneuvering speed (<14 kn) No 16-25 km from DWP Half ahead (<10 kn) No 5-16 km from DWP Slow ahead (<6 kn) No Inside 5 km from DWP Dead slow ahead (<4.5 kn, decreasing to <3 kn) Bow and stern thrusters Docking Dead slow Two bow thrusters; possibly one or two stern thrusters

Based on a regasification cycle of approximately 8 days and projected DWP throughput during the first several years of 400 MMscfd, vessel traffic during operations is projected to consist of a maximum of 46 SRV trips per year. During DWP operations, sound would be generated by the maneuvering of SRVs upon approach to the Port, regasification of LNG aboard the SRVs, and subsequent debarkation from the Port.

Once an SRV is connected to a buoy, the vaporization of LNG and send-out of natural gas can begin. Each SRV would be equipped with up to five vaporization units, each with the capacity to vaporize 250 MMscfd. Under normal operation, two or more units would be in service simultaneously, with at least one unit on standby mode.

Method of Incidental Taking

Incidental take is anticipated to result from elevated levels of sound introduced into the marine environment by the construction and operation of the DWP, as described in preceding sections. Specifically, sound from pile driving, drilling, dredging, and vessel operations during the construction and installation phase, and sound from SRV maneuvering, docking, and regasification during operations would likely result in the behavioral harassment of marine mammals present in the vicinity. Table 3 shows these proposed activities by the time of year they are anticipated to occur.

Table 3—Projected Construction, Installation, and Operations Activities, by Season Activity Season Construction and installation Buoy installation Summer 2013 Offshore impact hammering Summer 2013 Pipelaying offshore Late Summer 2013 through early Winter 2013-14 Pipelaying inshore Late Summer 2013 through early Winter 2013-14 Offshore pipeline burial Fall 2013 through Winter 2013-14 Inshore pipeline burial Fall 2013 through Winter 2013-14 HDD Summer 2013 HDD vibratory driving Summer 2013 Operations SRV maneuvering/docking Year-round; maximum 46 visits per year Regasification Year-round; 8 days estimated per visit

During construction, underwater sound would be produced by construction vessels (e.g., barges, tugboats, and supply/service vessels) and machinery (e.g., pile driving and pipe laying equipment, trenching equipment, and goal post installation equipment at the HDD locations) operating either intermittently or continuously throughout the area during the construction period. Vessel traffic associated with construction would be a relatively continuous sound source during the construction phase. Vessel sound would be created by propulsion machinery, thrusters, generators, and hull vibrations and would vary with vessel and engine size. Machinery sound from underwater construction would be transmitted through water and would vary in duration and intensity. Port construction (i.e., field construction and installation operations) would require approximately 11 months.

While the main sound source during SRV transit and approach to the DWP would originate from the SRV main engines (i.e., predominantly in low frequencies), the primary sound source during maneuvering and docking would be the SRV thrusters. An additional underwater sound source would be the sound produced by the flow of gas through the proposed pipeline, although very little sound would be expected to result (JASCO, 2008); therefore, this source is not considered further.

Description of Sound Sources

Sound travels in waves, the basic components of which are frequency, wavelength, velocity, and amplitude. Frequency is the number of pressure waves that pass by a reference point per unit of time and is measured in hertz (Hz) or cycles per second. Wavelength is the distance between two peaks of a sound wave; lower frequency sounds have longer wavelengths than higher frequency sounds, which is why the lower frequency sound associated with the proposed activities would attenuate more rapidly in shallower water. Amplitude is the height of the sound pressure wave or the “loudness” of a sound and is typically measured using the decibel (dB) scale. A dB is the ratiobetween a measured pressure (with sound) and a reference pressure (sound at a constant pressure, established by scientific standards), and is a logarithmic unit that accounts for large variations in amplitude; therefore, relatively small changes in dB ratings correspond to large changes in sound pressure. When referring to sound pressure levels (SPLs; the sound force per unit area), sound is referenced in the context of underwater sound pressure to 1 microPascal (μPa). One pascal is the pressure resulting from a force of one newton exerted over an area of one square meter. The source level (SL) represents the sound level at a distance of 1 m from the source (referenced to 1 μPa). The received level is the sound level at the listener's position.

Root mean square (rms) is the quadratic mean sound pressure over the duration of an impulse. Rms is calculated by squaring all of the sound amplitudes, averaging the squares, and then taking the square root of the average (Urick, 1975). Rms accounts for both positive and negative values; squaring the pressures makes all values positive so that they may be accounted for in the summation of pressure levels (Hastings and Popper, 2005). This measurement is often used in the context of discussing behavioral effects, in part because behavioral effects, which often result from auditory cues, may be better expressed through averaged units than by peak pressures.

When underwater objects vibrate or activity occurs, sound-pressure waves are created. These waves alternately compress and decompress the water as the sound wave travels. Underwater sound waves radiate in all directions away from the source (similar to ripples on the surface of a pond), except in cases where the source is directional. The compressions and decompressions associated with sound waves are detected as changes in pressure by aquatic life and man-made sound receptors such as hydrophones.

The underwater acoustic environment consists of ambient sound, defined as environmental background sound levels lacking a single source or point (Richardsonet al.,1995). The ambient underwater sound level of a region is defined by the total acoustical energy being generated by known and unknown sources, including sounds from both natural and anthropogenic sources. These sources may include physical (e.g., waves, earthquakes, ice, atmospheric sound), biological (e.g., sounds produced by marine mammals, fish, and invertebrates), and anthropogenic sound (e.g., vessels, dredging, aircraft, construction). Even in the absence of anthropogenic sound, the sea is typically a loud environment. A number of sources of sound are likely to occur within Tampa Bay and the adjoining shelf, including the following (Richardsonet al.,1995):

Wind and waves:The complex interactions between wind and water surface, including processes such as breaking waves and wave-induced bubble oscillations and cavitation, are a main source of naturally occurring ambient sound for frequencies between 200 Hz and 50 kHz (Mitson, 1995). In general, ambient sound levels tend to increase with increasing wind speed and wave height. Surf sound becomes important near shore, with measurements collected at a distance of 8.5 km (5.3 mi) from shore showing an increase of 10 dB in the 100 to 700 Hz band during heavy surf conditions.

Precipitation sound:Sound from rain and hail impacting the water surface can become an important component of total sound at frequencies above 500 Hz, and possibly down to 100 Hz during quiet times.

Biological sound:Marine mammals can contribute significantly to ambient sound levels, as can some fish and shrimp. The frequency band for biological contributions is from approximately 12 Hz to over 100 kHz.

Anthropogenic sound:Sources of ambient sound related to human activity include transportation (surface vessels and aircraft), dredging and construction, oil and gas drilling and production, seismic surveys, sonar, explosions, and ocean acoustic studies (Richardsonet al.,1995). Shipping sound typically dominates the total ambient sound for frequencies between 20 and 300 Hz. In general, the frequencies of anthropogenic sounds are below 1 kHz and, if higher frequency sound levels are created, they would attenuate (decrease) rapidly (Richardsonet al.,1995). Typical SPLs for various types of ships are presented in Table 4.

Table 4—Underwater SPLs for Representative Vessels Vessel description Frequency (Hz) Source level (dB) Outboard drive; 23 ft; 2 engines @ 80 hp 630 156 Twin diesel; 112 ft 630 159 Small supply ships; 180-279 ft 1,000 125-135 (at 50 m) Freighter; 443 ft 41 172 Source: Richardsonet al.,1995.

The sum of the various natural and anthropogenic sound sources at any given location and time—which comprise “ambient” or “background” sound—depends not only on the source levels (as determined by current weather conditions and levels of biological and shipping activity) but also on the ability of sound to propagate through the environment. In turn, sound propagation is dependent on the spatially and temporally varying properties of the water column and sea floor, and is frequency-dependent. As a result of the dependence on a large number of varying factors, the ambient sound levels at a given frequency and location can vary by 10-20 dB from day to day (Richardsonet al.,1995).

Very few measurements of ambient sound from Tampa Bay and the adjoining shelf are available. There are no specific data on ambient underwater sound levels for the area of the proposed Port and pipeline route. Shooteret al.(1982) analyzed approximately 12 hours of data collected in deep (3,280 m) waters in the western GOM and reported median ambient sound levels of 77-80 dB re: 1 μPa2/Hz. These levels are likely to be somewhat lower than those occurring in the vicinity of Tampa Bay, due in large part to the reduced contribution from surf in deep water.

Known sound levels and frequency ranges associated with anthropogenic sources similar to those that would be used for this project are summarized in Table 5. Details of each of the sources are described in the following text.

Table 5—Anticipated Source Levels for Construction/Installation and Operations at the Port Dolphin DWP Source Activity Location Maximum
  • broadband
  • source level
  • (re: 1 µPa)
  • Barge Anchor installation operations STL buoys (DWP) 177 dB Tug Anchor installation operations STL buoys (DWP) 205 dB Impact hammer1 Pile driving STL buoys (DWP) 217 dB Barge Pipe laying Pipeline corridor, DWP to shore 174 dB Tug Transit Offshore/Inshore 191 dB Dredge Dredging Likely inshore, offshore if necessary 188 dB HDD Drilling Two locations in Tampa Bay 157 dB Vibratory driving Sheet pile installation Two locations in Tampa Bay 186 dB SRV Maneuvering/docking, with thrusters DWP 183 dB SRV Regasification DWP 165 dB Source: JASCO, 2008, 2010. 1Source level for impact hammer estimated assuming pulse length of 100 ms.

    The sounds produced by these activities fall into one of two sound types: Pulsed and non-pulsed (defined in next paragraph). The distinction between these two general sound types is important because they have differing potential to cause physical effects, particularly with regard to hearing (e.g., Ward, 1997 in Southallet al.,2007). Please see Southallet al.(2007) for an in-depth discussion of these concepts.

    Pulsed sounds (e.g., explosions, gunshots, sonic booms, impact pile driving) are brief, broadband, atonal transients (ANSI, 1986; Harris, 1998) and occur either as isolated events or repeated in some succession. Pulsed sounds are all characterized by a relatively rapid rise from ambient pressure to a maximal pressure value followed by a decay period that may include a period of diminishing, oscillating maximal and minimal pressures. Pulsed sounds generally have an increased capacity to induce physical injury as compared with sounds that lack these features.

    Non-pulse (intermittent or continuous) sounds can be tonal, broadband, or both. Some of these non-pulse sounds can be transient signals of short duration but without the essential properties of pulses (e.g., rapid rise time). Examples of non-pulse sounds include those produced by vessels, aircraft, machinery operations such as drilling or dredging, vibratory pile driving, and active sonar systems. The duration of such sounds, as received at a distance, can be greatly extended in a highly reverberant environment. Many of the sounds produced by the project would be transient in nature (i.e., the source moves), such as during vessel docking. Regasification sounds are continuous (while the SRV is docked) and stationary. The positioning (maneuvering and docking) of SRVs using thrusters is intermittent (i.e., every 8 days) and of short duration (i.e., 10 to 30 minutes).

    For this project, the only pulsive sounds are associated with pile driving activities at the offshore Port location (i.e., associated with anchor installation activities). Impact hammers (proposed for use in driving buoy anchors) operate by repeatedly dropping a heavy piston onto a pile to drive the pile into the substrate. Sound generated by impact hammers is characterized by rapid rise times and high peak levels, a potentially injurious combination (Hastings and Popper, 2005). Vibratory hammers, which would be used to install sheet pile and possibly pilings for goal posts inshore, install piles by vibrating them and allowing the weight of the hammer to push them into the sediment. Vibratory hammers produce significantly less sound than impact hammers. Peak SPLs may be 180 dB or greater but are generally 10 to 20 dB lower than SPLs generated during impact pile driving of the same-sized pile (Caltrans, 2009). Rise time is slower, reducing the probability and severity of injury (USFWS, 2009), and sound energy is distributed over a greater amount of time (Nedwell and Edwards, 2002; Carlsonet al.,2001).

    Sound Attenuation Devices

    Sound levels can be greatly reduced during impact p