- Chapter 2 - Description of the Proposed Action and Alternative
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Alternative A
Under Alternative A, the western edge of the USWTR would be located 93 km (50 NM) east of Florida’s northeastern shoreline. Installation of the USWTR at the proposed Site A, as at all proposed sites, would entail the placement of no more than 300 transducer nodes in water depths ranging from approximately 37 to 366 meters (120 to 1,200 feet) over an approximately 1,713-square kilometer (500-square nautical mile) area. As with Site D, off Virginia, the interconnect cable between each node may be buried in the shallower depths at Site A and D due to potential entanglement concerns related to bottom-trawling fishing gear (there is more intensive bottom trawling in the vicinity of Sites A and D than in the vicinity of Sites B and C). In deeper waters, the interconnect cable would not be buried. The trunk cable would run from the range area to the cable termination facility (CTF) located on shore; it would be buried to a depth of approximately 0.5 to 1 meter (1 to 3 feet).
The trunk cable would either be directly buried in an armored cable or encased in a protective pipe on shore at Naval Station Mayport. Commercial power and telecommunications connections would be made to the Naval Station Mayport infrastructure. The communications signals would be routed to the range operations center (ROC) at FACSFAC JAX and VACAPES and electronics would be housed at the terminal end of the communications link.
Alternative B
The proposed Site B USWTR would be located approximately 70 km (38 NM) offshore of central South Carolina. The interconnect cable between each of the nodes would be buried if deemed necessary. The trunk cable connecting the range to the CTF located on shore would be buried to a depth of approximately 0.5 to 1 m (1 to 3 ft).
Onshore, Ft. Moultrie on Sullivan’s Island, provides a possible shore landing site for the cable. The trunk cable would either be directly buried in an armored cable or encased in a protective pipe on shore. Power and telecommunications connections would be made with the Ft. Moultrie National Monument. The communications signals would be routed to the ROC at FACSFAC VACAPES and electronics would be housed at the terminal end of the communications link.
Alternative C
Under this alternative, the edge of the USWTR would be located about 86 km (47 NM) offshore of southeastern North Carolina. The interconnect cable between each node might be buried. The trunk cable connecting the range to the cable termination facility (CTF) located on shore would be buried to a depth of approximately 0.5 to 1 m (1 to 3 ft).
Onshore, the Marine Corp Base Camp Lejeune in Jacksonville, North Carolina, provides a possible shore landing site for the cable. The cable would be buried in a conduit. Data would be sent from the CTF to the Starling communication site at MCB Camp Lejeune and then to the ROC at FACSFAC VACAPES, and electronics would be housed at the terminal end of the communications link.
Alternative D
Under Alternative D, the edge of the USWTR would be located 63 km (34 NM) east of Virginia’s northeastern shoreline. The interconnect cable between each node may be buried in the shallower depths at Site D due to potential entanglement concerns related to bottom-trawling fishing gear. In deeper waters, the interconnect cable would not be buried. The trunk cable connecting the range to the CTF located on shore would be buried to a depth of approximately 0.5 to 1 m (1 to 3 ft).
The trunk cable would be installed either directly buried in an armored cable or encased in a protective pipe at the NASA Wallops Flight Facility (WFF) . Commercial power and telecommunications connections would be made to the NASA WFF infrastructure. The communications signals would be routed to the ROC at FACSFAC, and electronics would be housed at the terminal end of the communications link.
No Action Alternative
CEQ regulations provide that a No Action Alternative should be included in the analysis of alternatives and associated impacts. The No Action Alternative represents the existing conditions at the USWTR locations and is used as the baseline alternative against which the magnitude of impact of constructing and operating a shallow water ASW range is evaluated.
Under the No Action Alternative, no USWTR would be installed off the east coast of the U.S. However, under the No Action Alternative, active sonar activities would continue across Navy OPAREAs and adjacent areas in a manner that maximizes training and RDT&E (research, development, testing and evaluation) opportunities; and ASW training would continue to take place. Subsurface training involves the use of passive and active sonar during simulated attacks on surface ships or submarines. A detailed analysis of current ASW training impacts is contained in the Navy’s Final EIS/OEIS for Atlantic Fleet Active Sonar Training, December 2008.
Although a No Action Alternative would not prevent the Navy from maintaining ASW readiness, the No Action Alternative would be detrimental to training efficiency and effectiveness primarily because it lacks timely feedback of performance data to participating units.
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