Table IV.G-2. Continued Source/Action Hydroelectric Domestic non-OCS Oil NOTE: SOURCE: Detailed information on these and other energy sources and their A Comparative Analysis (University of Oklahoma, 1975), prepared for FEIS, 1982, St. George Basin, Minerals Management Service Alaska Conclusion: Cancelling the proposed sale would eliminate all of the adverse impacts projected to occur under Alternative 1. Also, this action would eliminate the majority of impacts associated with existing leases, since future development of existing leases is unlikely in the absence of future leasing activity in the mid-Atlantic or the discovery of commercial quantities of oil and gas resources on the existing leases. However, impacts associated with imported crude and refined products would still occur. IV.H. Alternative 4: NASA Deferral. Modify the Proposal by Deferring Blocks to Avoid Operationals Conflicts with NASA Activities This alternative consists of deferring 65 blocks (approximately 2 percent of the sale area) within protraction diagram NJ 18-8 (see figure II.B.4-1). NASA's Wallops Island Flight Facility at Wallops Island, Virginia, identified these 65 blocks to be within their surface-free flight zone. Deferral of these blocks will eliminate the remote possibility of an exploratory rig and/or production platform being damaged by falling debris from rocket and missile test conducted by NASA and Wallops Island. The conditional mean resource estimates for this alternative are 190 mmbbl of oil and 3.3 tcf. of gas. The development scenario will remain the same as the proposed action; one gas pipeline and tanker transport of oil to refineries on the Delaware and Raritan Bays (see Appendix B for more details). IV.H.1. Impacts on and Benthic Organisms and Plankton Under this alternative, any distinct benthic communities located in Washington Canyon would be protected. Benthic communities and plankton in the deferred area would not be exposed to chronic, low-level discharges associated with drilling activities. Because deferral of these blocks under this alternative will only slightly decrease the estimated hydrocarbon resources for the sale area, the overall impacts on benthos and plankton will be similar to the impacts expected under the proposed action. Conclusion: Under this alternative, impacts to the benthos are expected to be moderate and impacts to plankton are expected to be minor. IV.H.2. Impacts on Fish and Commercial Fishery Resources Deferral of 65 blocks, or approximately 2 percent of the proposed sale area, located off the coast of Virginia, is proposed to reduce potential conflicts with NASA activities. The proposed deferral area encompasses portions of the continental shelf, slope, and rise, as well as Washington Canyon. These habitats contain most of the species described in Sections III.B.3 and III.C.3. Because of the location of these blocks in the pathway of several migrating pelagic finfish such as Atlantic mackerel, menhaden, and several tunas, it is a valuable area of the mid-Atlantic. In addition, offshore spawning species such as summer flounder, black seabass, bluefish, and scup utilize these waters during spring and summer for spawning. Shelf-slope and canyon assemblages within the deferral area are essentially the same as described in Section III.B.3, with the exception of the majority of the tilefish population which is concentrated north of this area. Sport fishing activities include a relatively intensive offshore billfish fishery conducted during the summer from ports along the coasts of Maryland and Virginia. If the designated 65 blocks are deferred, the principal benefit is the elimination of chronic drilling discharges within the deferral area. The preclusion of drilling in the deferral area would eliminate potential impacts on fragile canyon and shelf-slope habitats in this localized area. Also reduced would be the amount of space lost to commercial fishermen by the location of drilling rigs and platforms. Because the deferral area is very small, and the fact that most commercial fisheries analyzed in Section IV.E.7 are located in shallower waters, the change in revenue lost to commercial fishermen described for the proposed action would be essentially the same as for this deferral alternative. The factors with the greatest potential to affect mid-Atlantic fish and fishery resources such as a platform blowout of 1,000 barrels or greater or a tanker spill in relatively shallow water would still be expected to possess the same probability of recurrence, even if this deferral alternative were adopted. Therefore, the type and severity of impacts described for the proposed action are essentially the same anticipated for this alternative. Conclusion: Impacts on mid-Atlantic fish and fishery resources, in general, will be low, with populations demonstrating local declines in abundance and/or distribution, but recovering to their pre-impact condition within 1 year, and the populations, as a whole, are not affected. The level of impact on marine and coastal birds under this alternative would be essentially the same as offering the entire sale area. Although no drilling activity could take place on the 65 deferred blocks (approximately 2 percent of the sale area), this would not be a significant benefit to these birds because of the distance from shore of these blocks (over 50 miles) and because it is not an area of known importance to marine birds. In addition, because no significant change is anticipated in the amount of recoverable resources and the development and production scenario, the risk of an oil spill occurring and contacting seabirds and the estimated number of spills will remain the same as what was discussed under the proposed action. Conclusion: A minor level of impact on marine and coastal birds is anticipated under this alternative. IV.H.4. Impacts on Sensitive Coastal Habitats Under this alternative the amount of recoverable hydrocarbons and the associated oil spill risk to coastal areas is essentially the same as what is projected under the proposed action. The proposed deferral area is over 50 miles from shore and comprises approximately 2 percent of the sale area. The absence of drilling activities in this area would not have a significant effect on coastal areas. In addition, no reduction in the number of pipeline landfalls, gas processing facilities, or operation support bases are expected under this alternative. Conclusion: A negligible level of impact on estuaries, wetlands, and sensitive coastal areas is anticipated under this alternative. IV.H.5. Impacts on Endangered and Threatened Species and The level of impact on endangered and threatened species should not decline significantly under this alternative. The distance from shore of the proposed deferral area is over 50 miles. Because of this distance, deferral of this area would not have a positive effect on coastal species. The proposed deferral area is very small (approximately 2 percent) in comparison to the remainder of the sale area. Because of the relatively small size of the deferral area, the estimated recoverable resources and impacts associated with development and production from the remaining blocks will continue to pose a minor threat to all species. The absence of drilling activities in these waters should benefit sea turtles that feed in the vicinity and fin whales that may calve in the waters off the Delaware and Maryland shore (CETAP, 1982). However, impacts on whales and sea turtles from OCS activities should only be minor because of the wide ranging behavior of these animals and the low level of anticipated exploration, development, and production activities. Conclusion: A minor level of impact on all endangered and threatened species except the right whales (moderate) is anticipated under this alternative. IV.H.6. Conflicts with NASA/DOD Activities Since all blocks within NASA's Wallops Island surface-free zone (free of all surface structures) would be deferred under this alternative, potential conflicts between NASA activities and OCS surface structures (exploratory rigs and production platforms) would be eliminated. A conflict between NASA activities in the surface-free zone and OCS activities, however, may occur if it is found necessary for a pipeline to traverse the surfacefree zone. This potential conflict would be of short duration, lasting only long enough for the installation of the pipeline. Oil and gas operations in DOD warning and operating areas can be coordinated with DOD activities through the notification requirements in the military stipulation (see Section II.B.d.). Conclusion: The impact of OCS activity on NASA/DOD activities will remain negligible under this alternative, as under the proposal. IV.I. Alternative 5: Canyon Area Deferral. Modify the Proposal by Under this alternative, 59 whole blocks and 54 partial blocks would be deferred from the sale (see Table II.B.5). The area deferred if this alternative is selected would be approximately 499,680 acres or about 2.5 percent of the sale area. The resource estimate would decrease by 10 mmbbl or 5 percent if this alternative is chosen. The blocks and partial blocks selected for inclusion in deferral Alternative 5 were identified based upon criteria used by NOAA to define canyon blocks deferred from the North Atlantic Sale No. 82. In addition, a 200 m "no occupancy buffer zone" was included around each canyon head and incorporated into the final area designated for deferral under this alternative. The adoption of this alternative would eliminate the impacts to the more concentrated benthic organisms which are found in the defined canyon areas. The increased biological productivity in these areas is derived from the attached filter feeding organisms which find suitable substrate in the rugged canyon heads and which would be susceptible to elevated turbidity levels resulting from drilling operations or to direct mechanical damage. A number of benthic organisms are known to burrow, or inhabit burrows dug, into the Pleistocene clay scarps found in the heads of submarine canyons. These "pueblo-village communities" would be vulnerable to well-head placement and increased sedimentation resulting from drilling operations, but would not be appreciably at risk if Alternative 5 is selected. Alternative 5 would not decrease the expected number of spills of 1,000 bbl or greater resulting from the proposed action. Therefore, the risk to the canyon head areas from a surface oil spill will remain approximately the same, but it is expected that these areas are in deep enough water to not be directly affected by advected oil. Hydrocarbons from a surface slick may be introduced to these canyon areas by being incorporated into or adsorbed on detrital particles or zooplankton fecal pellets but would be widely dispersed, and no detectable impact is expected to result. Accepting deferral Alternative 5, however, would eliminate the possibility of a well-head blowout occurring in a submarine canyon and would prevent the associated impacts to the benthic canyon assemblages. Impacts Conclusion: Impacts to canyon assemblages would be severely reduced. |