IV.L. Irreversible or Irretrievable Commitment of Resources Leasing of the proposed blocks and subsequent development and extraction of hydrocarbons could represent an irreversible and irretrievable commitment of nonrenewable oil and gas resources. The conditional mean resource estimates for the proposed sale are 200 million barrels of oil and 3.6 tef of natural gas. An irreversible or irretrievable commitment of biological resources and their habitats could occur in the area of a massive oil spill, or near areas that are subjected to chronic low levels of pollution. It is anticipated that an affected area would recover from a spill and that the natural flora and fauna would eventually reoccupy spill areas. Exceptions could be an irreversible or irretrievable loss of an endangered species that may result if populations of such a species are affected by an oil spill, either directly or through food contamination, or by any other disruption or disturbance such as habitat loss that may result from the proposed sale. Deaths and permanent disabilities from OCS offshore operations are an irretrievable loss of human resources. During the period between 1970 and 1978, there were 139 fatalities and 212 injuries from such activities on the U.S. Gulf of Mexico OCS. In February, 1982 the oil rig "Ocean Ranger" capsized in a storm off the Canadian coast with a loss of 83 lives. The proposed sale would require land for a right-of-way for one natural gas pipeline and associated processing facility and for one operation support base. Additional land for facilities stimulated in part by this proposed sale could also be required. A decision to proceed with proposed Sale No. 111 would result in the production of certain OCS-related goods and services. To the extent that resources would be drawn away from other uses, production of goods and services in other areas or of other types would be foregone. IV.M. High Resource Estimate Scenario Introduction Economically recoverable resources under the high resource scenario are estimated at 430 mmbbl of oil and 7 tcf of gas. Exploration under the high resource scenario would begin in 1987 and continue through 1994 with 47 exploratory and delineation wells being drilled. Actual production of oil under this scenario is scheduled to begin in 1995 and peak in 1999 at 43 mmbbl or approximately 120,000 bbl/d. Gas production would commence in 1998 with peak production of 2 bcf/d (Sale No. 111 and currently leased lands) being reached one year later. This peak level of production will be sustained under 2007 when production will begin to decline. Production of both oil and gas will continue until 2024. The high resource estimate calls for 31 exploratory wells (a 50 percent increase over the mean scenario) and 8 platforms (a 100 percent increase over the mean scenario). Of the 8 platforms called for under the high resource scenario 2 would be in shallow water containing equipment for the 38 subsea completions. The remaining 6 platforms would all be located in deep water and service 48 production wells. Oil produced under the high resource scenario would be loaded onto tanker trips from platforms or from single point moorings corrected by gathering lines to subsea complexes. It is estimated that approximately 11 tankers per month (50,000 DWT) would be necessary to transport the peak annual (1999) production of oil to refineries on the Raritan and Delaware Bays. Gas produced under this scenario would be gathered by 300 mi of small diameter gathering pipe and fed into two 36-inch trunk lines. These trunk lines would terminate at the two landfalls described in the mean scenario. Gas facilities: One gas processing and/or dehydration plant is projected to be associated with each of the landfalls. These gas facilities are projected to have a capacity of approximately 2 bcf/d to accommodate the peak gas production from Sale No. 111 and the gas produced from previously leased lands. Support bases: The high resource estimate scenario would utilize the same two support bases described in the mean scenario: Hampton Roads, Virginia and Washington County, Rhode Island. Platform Fabrication and Pipecoating: All platform fabrication needed under the high resource scenario will most likely occur at existing fabrication facilities in the Gulf of Mexico Region. Pipecoating will most likely occur at one of several existing facilities within the mid-Atlantic region. Types of water quality impacts for the high resources estimate would be the same as those described for the mean estimate. The magnitude of these impacts, however, would be greater, as the number of wells and platforms would be approximately double (82 percent increase in number of wells and 100 percent increase in platforms) of that assumed for the mean resource estimate. Consequently, volumes of drilling muds and cuttings, formation waters, low-level oil releases, and domestic/sanitary wastes would increase proportionately. However, the volumes of these materials would still be small compared to the large volume of receiving water. The materials would be rapidly dispersed/ diluted, and their discharge would take place within a geographically large area, spaced over a long period of time--a total exploration and production period of 38 years: 13 years for the drilling of wells and 30 years for resource production. Because of these factors, impacts on water quality due to these routine discharges would be temporary and minor in nature. Minor to moderate impact on water quality is anticipated from a large oil spill. Impact from large (greater than 1,000 barrels) oil spills increases as does the probability of such spills occurring and reaching shallower coastal areas. Although the assumed number of spills (one) greater than 1,000 barrels for the high resource scenario is the same as for the mean resource (Alternative 1) estimate (Section IV.B.3.), the probability of such a spill occurring in or reaching a shallow coastal area as measured by "land" contact in the OSRAM model, increases from 6 percent to 15 percent (Tables 12 and 15, Appendix C). In summary, routine discharges (drill muds and cuttings, formation waters, low-level oil releases, domestic and sanitary wastes) would result in localized and temporary changes in ambient water quality. A large oil spill, although likely to have only a temporary effect, may severely degrade water quality if occurring in or reaching shallower coastal areas. Conclusion: A moderate impact on water quality is projected for the high resource estimate scenario. IV.M.2. Impacts on Benthic Organisms and Plankton Under the high resource estimate scenario an additional 14 exploratory and production wells will be drilled. This will increase the discharge of muds and cuttings by an additional 287,340,661 (45,684 m3) to 329,340 bbl (52,362 m3) over the volumes estimated for the proposed action. However, these additional drilling discharges consisting of muds, cuttings, and formation waters, will be spaced over a 12-year period, localized, and short-term. The expected number of oil spills of 1,000 bbl or greater will remain the same under the high resource estimate scenario as for the proposed action. Therefore, no change in impact levels on benthic organisms and plankton is expected as a result of the high resource estimate scenario. Conclusion: A moderate impact on benthic organisms and a minor impact on plankton is expected under the high resource estimate scenario. IV.M.3. Impacts on Marine and Coastal Birds The degree of impact on marine and coastal birds would be expected to increase under the high resource estimate scenario. Important breeding and feeding habitats in the vicinity of the Raritan and Delaware Bays, Nantucket Island, and Long Island, New York will continue to be the most vulnerable areas to any OCS-related oil spills. However, the probability of an oil spill occurring and contacting these habitats would increase in response to the increase in the expected volume of recoverable crude oil. If seabirds are exposed to spilled oil, large numbers of birds could perish. Repeated exposures could wipe out local populations and lead to population declines on a regional basis. The additional support base and gas pipeline landfall are not expected to seriously affect breeding or feeding habitats because they are assumed to be located in an existing port and in areas of low value to coastal birds, respectively. The increase in the number of wells drilled and production platforms (approximately 100 percent increase) and their associated discharges may degrade the water quality of marine habitats important to sea ducks and pelagic species. Using the estimates for volumes of formation waters and concentrations of hydrocarbons assumed in Section IV.E.3, the volume of crude oil discharged in formation waters over the life of the field may increase by approximately 115 percent (from 4,000 to 8,600 barrels). The volume of drill muds and cuttings discharged would also increase by about 100 percent. duction of drill muds and cuttings and crude oil into the mid-Atlantic ecosystem may pose a long-term threat to the seabirds inhabiting the region. Because of the low crude oil resource estimate (430 million barrels), no Conclusion: Impacts on marine and coastal birds could increase to a moderate level under the high resource estimate scenario. The level of impact on estuaries, wetlands, and sensitive coastal habitats is expected to increase if the high resource estimate is discovered in the sale area. Important coastal habitats and beach areas in the vicinity of the Raritan and Delaware Bays, Nantucket Island, and Long Island, New York would continue to be the areas most vulnerable to a sale-related spill. Although the assumed number of spills remains only one, the risk of a spill occurring and contacting these sensitive areas increases (Table 15, Appendix C). The probability of a spill occurring and contacting coastal marshes, wildlife refuges, or the Massachusetts Ocean Sanctuary within 30 days increases from 2 to 8 percent. This increase indicates that the high resource estimate scenario will pose a greater oil spill risk to sensitive coastal areas. The one additional support base in Virginia and gas pipeline landfall in Delaware assumed in this scenario are not expected to result in any significant loss of coastal habitats. It is assumed that they would be located in an existing port and in an area supporting existing development, respectively. Conclusion: A moderate level of impact on sensitive coastal areas is anticipated under the high resource estimate scenario. IV.M.5. Impacts on Endangered and Threatened Species and Impacts on endangered or threatened birds and coastal species would not be expected to increase if the high resource estimate is developed. Important habitats for endangered birds and coastal species in the vicinity of the Raritan and Delaware Bays, the south shore of Long Island, and the waters south of Cape Cod remain the most vulnerable areas to any OCS-related oil spills. The probability of an oil spill occurring and contacting peregrine falcon migratory stop-over areas (4 percent) and bald eagle nesting sites (less than 0.5 percent) under the high resource scenario are very low (see Table 15, Appendix C). The one additional pipeline landfall, gas processing plant, and support base are expected to be located in areas currently zoned for industry. Therefore, the minimal change in oil spill risk to these species together with the locating of additional facilities in industrial areas indicate that the high resource scenario should have only a minor effect on birds and coastal species. Impacts on sea turtles and marine mammals could increase as a result of the increased level of drilling activity and support vessel traffic. The number of wells drilled, support vessels, and volumes of discharged drill muds, cuttings and formation waters could double if oil under the high resource estimate is discovered and produced. The increased number of drilling platforms could adversely affect whales by the sounds they produce and by their presence in feeding, breeding, or migratory areas. The increase in volumes of discharged materials could adversely affect the food sources of both turtles and whales in the vicinity of the drill rig or production platform. An increase in support vessel traffic would correspondingly increase the risk of collision between these vessels and endangered marine species. However, the number of oil spills (one) assumed for the high resource scenario is the same as the one for the proposed action. The oil spill risk to preferred right whale areas and humpback and fin whale feeding grounds increases by only 4 percent (Table 15, Appendix C). In addition, the most critically endangered whale (right whale) and sea turtle (Atlantic ridley) species are not known to concentrate within the boundary of the sale area. Conclusion: Under the high resource estimate scenario, a minor level of impact is projected for endangered birds and coastal species, but sea turtles and marine mammals could experience a moderate level impact under this scenario. |