Both harbor and docking pilots agreed that this configuration would not impact present navigation practices between Stations 58+000 and 59+000 (mile 11.0-11.2), but any restrictions less than a 400-foot wide channel in the reach would be unacceptable. At the present time, no deepening would be required to be performed between Stations 58+000 and 59+000 (mile 11.0-11.2). If future ship traffic above that which is projected requires widening of this reach, the wreck would probably have to be relocated and the fort's foundation reinforced and protected. Union Camp Corporation, which has a paper mill on the south side of the river, has a buried pipeline crossing the river at Station 88+750 (mile 16.8). The top of the pipe is approximately at elevation -47 feet mean low water. It is a fiberglass auxiliary pipe which carries effluent from the paper mill to an aeration lagoon on the north side of the river. Although the pipe is not presently used, Union Camp has been maintaining the pipe as a backup to a newly installed pipeline. A new pipeline is located at Station 89+250 (mile 16.9). It was a direct bore and is located at elevation -65 feet mean low water at the toe of the slope. The old pipe was installed in an open trench which was not backfilled, and it has ruptured on a few occasions. It is speculated that the ruptures were caused by submerged debris. Recent sidescan sonar surveys do not indicate debris above the river bottom, but there could be some debris that was trapped in the trench and subsequently covered by drifting bedload shoal material. It is possible that buried debris could be encountered during deepening dredging, and the pipeline could possibly be damaged when the debris is removed. The pipeline is also susceptible to damage from a dredge cutterhead, spuds, and/or swing anchors. Union Camp was issued a Department of the Army permit for the installation of the pipe. No damage to dredge cutterheads would result from encounter with the pipeline or adjacent debris. When informed of the proposed project deepening, Union Camp recently decided to abandon the pipeline. There will be no costs associated with the pipeline. Navigation Aids Fixed range markers are used by the pilots to navigate the inner harbor. Thus, existing navigation aids in the harbor channel, including the 'wreck' buoy marking the location of the CSS GEORGIA, would be sufficient for safe harbor operations after channel deepening. No major realignments are contemplated at this time, therefore, sailing ranges would remain fixed. Some buoys, or other side channel markers, may require minor movements or relocations to accommodate deeper water or adjustments for side slope sloughing. The sea buoy in the entrance would require relocating as a result of the extension of the bar channel. The pilots recommended that two new buoys be placed between the relocated sea buoy and existing buoys 1 and 2. Disposal of Dredged Material at Tybee Island During the Preformulation Phase of the Savannah Harbor Comprehensive Study, the option of disposing of a portion of the dredged material from the bar channel on Tybee Island was evaluated. At that time, a hopper dredge was considered for removal of the material from the bar channel. The analysis concluded that it was not economically feasible to transport the bar channel dredged material to Tybee Island. Recently, due to environmental constraints on the dredging window, it was determined that a hydraulic pipeline dredge with spider barge and dump scows would be necessary for dredging the bar channel instead of a hopper dredge. This change in dredging equipment for the bar channel significantly enhanced the feasibility of disposing of a portion of the bar channel dredged material on the eroded beaches at Tybee Island. Before this option can be fully evaluated, there are several issues which must be examined, and some critical information will not be available until Preconstruction Engineering and Design. The following is a summary of the four major items which are needed before the feasibility of disposal at Tybee Island can be determined: (1) Results of boring samples and testing in the bar channel which are scheduled for completion during Preconstruction Engineering and Design. This is necessary to determine if the bar channel dredged material is of adequate size and free of pollutants, and is suitable material for beach disposal. (2) Evaluation of the costs of total ocean disposal versus partial disposal at Tybee Island. This would include a comparison of the transport of dredged material by dump scows to the north end of Tybee Island and rehandling for placement on the beach, versus use of a hydraulic pipeline dredge for direct pumping to the beach area. (3) Determination of environmental compliance and obtaining necessary environmental clearances. (4) Thorough coordination with State and local officials and public input to determine public acceptance of using bar channel material for beach disposal. These four items must be completed before it can be determined if it is economically and environmentally feasible to dispose of some of the bar channel dredged material at Tybee Island. WATER QUALITY CERTIFICATION AND CONSTRUCTION CONSTRAINTS The Georgia Department of Natural Resources provided a Water Quality Certification letter dated 5 September 1991 for the Savannah Harbor Deepening Project in accordance with Section 401 of the Clean Water Act, as amended. This letter was amended by a second letter dated 22 November 1991 which deleted the dredging ban below river mile 5.0 during the March 16-May 31 environmental window. Copies of both letters are included in Attachment 2, Pertinent Correspondence. The Georgia Water Quality Certification is contingent upon the following conditions: (1) All work performed during construction will be done in a manner So as not to violate applicable water quality standards. (2) No oils, grease, materials or other pollutants will be discharged from the conducted activities which reach public waters. (3) No dredging will be conducted during the striped bass spawning period from March 16 to May 31 of each year (amended by 22 November 1991 letter). (4) Before any dredging can be conducted during the period July 1 to September 30, the applicant must secure approval from the Environmental Protection Division of a plan for monitoring of dissolved oxygen in the vicinity of the dredging site. The plan must include provisions for suspension of dredging during any periods when D.O. values drop below 3.0 mg/l. Results of this monitoring must be submitted to the Georgia Environmental Protection Division, the Georgia Game and Fish Division, and the Georgia Coastal Resources Division within 30 days of the completion of each dredging operation. If the applicant does not maintain a satisfactory record of compliance with this condition, the Environmental Protection (5) Hopper dredging should be conducted during December through March. These are the times when sea turtles are least abundant in the area of the Savannah Ship Channel. Dredging should not be conducted outside these months without implementation of a conservation plan approved by Georgia Department of Natural Resources. This plan should include trawling to remove turtles from the path of the dredge. (6) The Georgia Department of Natural Resources recommends that a systematic trawl survey of the Savannah Channel be conducted to confirm the distribution and abundance of turtles in the channel in winter. Data from this survey is to be used to better delineate the times when dredging is least likely to impact sea turtles. (7) During December through March, dredge and support vessel speeds should be limited to less than 5 knots during nighttime operations. A trained whale observer should be on watch during daylight hours. If daily aerial surveys are conducted for right whales, the nighttime vessel speed limitation would only need to be enforced when a whale was spotted within 15 miles of the project area during the previous daily survey. (8) The removal of the tide gate in the Savannah Back River and the back fill of New Cut as proposed in the Joint Public Notice dated June 26, 1991 will be conducted prior to or concurrently with the deepening of the Savannah River Harbor Channel as proposed in the Joint Public Notice of April 19, 1991. South Carolina Water Quality Certification The South Carolina Department of Health and Environmental Control provided a Water Quality Certification letter dated 6 December 1991 for the harbor deepening project. A copy of the letter is included in Attachment 2, Pertinent Correspondence. The South Carolina Water Quality Certification is subject to the following conditions: (1) Prior to or concurrent with dredging of the Savannah Harbor, New Cut Channel must be filled and the Back River tide gates removed from operation. (2) Best Management Practices to control erosion during and following construction of dikes across New Cut Channel and the removal of the tide gates from operation must be implemented. (3) All effluent from Disposal Area 12 must be discharged to the Back River and none to the Wright River or its tributaries. Diversion of all maintenance dredging effluent from Disposal Area 12 to the Savannah Harbor side must be studied and the best means to divert all effluent from Wright River determined. The Savannah District must submit a time schedule for relocation of the weir structures at Disposal Area 12 to the Department prior to dredging of the Savannah Harbor. (4) Dredging of the Savannah Harbor must be limited, if possible, to the winter months (November 1 through March 1). (5) The Savannah District must implement the conditions listed in the EIS for the protection of manatees, sea turtles, and right whales during the dredging operation. REAL ESTATE REQUIREMENTS Real estate acquisition includes the purchase of a 'perpetual sloughing easement' over land that is essentially a 40-foot wide strip adjacent to the shoreward boundary of the recently acquired easement for the Savannah Harbor Widening Project. The sloughing easement estate which was approved and used for acquisition of lands for the widening project would be used for the deepening project. The deepening project affects 12 property owners on the north side of the river and 4 property owners on the south side. Lands were acquired from 11 of the 12 Owners on the north side for the widening project, while no lands were acquired on the south side for the widening project. A Real Estate Planning document with a gross appraisal was not completed for the deepening project. Cost estimates, both land payments and administrative costs, were made on the basis of recent experience with land acquisition for the widening project. Land figures are provided without benefit of property inspections or an updated market study. Cost estimates were made with the assumption that no improvements would be acquired and no severance damages would arise. Table 43 presents the real estate requirements for the deepening project. |