Table IV.C.2-1. Clean Atlantic Associates Equipment and Materials

Davisville, Rhode Island (serves North Atlantic OCS Operations)

II. Davisville, Rhode Island (serves Mid-Atlantic OCS Operations)

III. Morehead City, North Carolina (serves South Atlantic OCS Operations)

Source: Clean Atlantic Associates, 1982. Clean Atlantic Associates Contingency

Manual Update Sept. 8, 1982.

OCS Operating Order No. 7 requires that, prior to approval of a permit to conduct operations offshore, operators must have an approved contingency plan that ensures the availability of spill containment and cleanup equipment and trained personnel. States are notified when contingency plans are approved. The contingency plan must contain assurances that full response capability can be committed during an oil spill emergency, including specification of appropriate equipment and materials, their availability, and time needed for deployment. The plan must also include provisions for varying degrees of response effort depending on the severity of the spill. Provisions must be established for the following: early detection and timely notification of a spill to responsible agencies; specific response actions including identification of a response operating team; predesignation of an oil discharge response coordinator; preplanned location for an oil discharge response operations center; and provisions for disposal of recovered spilled material.

Containment and cleanup equipment must be maintained at strategic locations near the site of operations or within the area, at the discretion of the MMS Regional Supervisor, and is decided on a case-by-case basis. A Memorandum of Understanding between the Departments of the Interior and Transportation outlines the respective responsibilities of MMS and the Coast Guard regarding the supervision of abatement, containment, and cleanup efforts required by this OCS Order. Essentially, MMS is responsible for the coordination and direction of abatement measures, while the Coast Guard is responsible for containment and removal operations. However, primary cleanup responsibility for a spill rests with the operator.

OCS Order No. 7 gives MMS the authority to specify the location at which cleanup equipment is to be maintained during offshore drilling. With Coast Guard guidelines requiring a response to a spill within 6 to 12 hours, MMS can require Atlantic operators to maintain equipment offshore if response time cannot be met by shore-based operations. A Fast Response Unit (FRU) may be maintained on the rig or on a work boat with trained personnel for a rapid cleanup response. Additional cleanup equipment is available in Davisville, Rhode Island and could be on-site in the Mid-Atlantic within 14 to 24 hours after notification.

IV.C.4. Offshore Oil Pollution Compensation Fund

The Offshore Oil Spill Pollution Compensation Fund (33 CFR 135), established by Title III of the OCS Lands Act Amendments of 1978, provides an offshore oil spill liability fund. The funds are for cleanup costs and replacement or restoration costs of natural resources damaged or destroyed by a spill originating at OCS offshore facilities or surface vessels transporting oil from an offshore facility. The fund is generated by fees on OCSproduced oil and reimbursed by claims against operators or owners of the facilities responsible for spills. The fund is to be maintained at a level of no less than $100 million and no more than $200 million. Claims against the fund may be made for costs of spill cleanup and for damages caused by the spill.

IV.C.5. Status of Oil Spill Containment and Cleanup Capability

Although the technology for mitigating oil spills has advanced in recent years, and although the National Contingency Plan and the regulatory practices of the MMS provide some assurance of response within the limitations of existing technology, the physical circumstances surrounding a spill--the rate and volume of oil spilled, sea state, currents, and weather conditions may severely limit the effectiveness of cleanup efforts. The most difficult operating conditions for cleanup equipment are high seas, storms, rapid currents, ice, and problems posed by the rapid formation of water-in-oil emulsions (mousse). Also, at-sea response is only likely to be partially successful in preventing shoreline pollution of a major spill close to the coast.

The appropriate response to an oil spill in the mid-Atlantic would depend on the physical and chemical properties of the oil and the extent to which the oil spreads, evaporates, disperses, or forms water-in-oil emulsions (mousse). Many treatment methods exist, and include mechanical recovery, chemical dispersal, absorbing, and burning. Current state-of-the-art equipment is reported to be capable of at least partial mechanical containment and recovery operations in 8 to 10 ft seas and 20 kt winds (U.S. Coast Guard Correspondence, April, 1981). An Offshore Devices skimming barrier system was used by the National Strike Force for containing and collecting oil from the Ixtoc I blowout in the Gulf of Mexico, Bay of Campeche. It was reported to exceed specified operational and survival estimates without significant failure of any physical barrier component (O'Brien, 1981). A recovery rate of up to approximately 300 gallons per minute was observed (U.S. Coast Guard Correspondence, April 9, 1981).

During the Ixtoc I blowout, a variety of cleanup techniques including skimmers, dispersants, and the Sombrero oil collection device were used to recover spilled oil. Only 4.5 percent of the 140 million gallons of oil was eventually recovered (50 percent burned at the well site, 17 percent evaporated, and 28.5 percent formed a slick). Although poor response management, mechanical failure, logistical problems, and suspension of operations for diver safety were contributing factors to the low recovery rate, many private contractors and government officials expressed agreement that, given similar weather conditions (tropical storms and rough seas), it would be difficult to improve the recovery rate. The PEMEX on-scene coordinator expressed doubt that the cleanup technology existed anywhere to deal effectively with a similar open ocean spill (Golob and McShea, 1981).

As discussed in section III.A.2 (Physical Oceanography), the severest conditions in the mid-Atlantic occur in fall and winter. During spring and summer waves are generally small. On an annual average, wave heights of less than 4 ft occur approximately 55 to 59 percent of the time, and waves greater than 12 ft occur 1 to 2 percent of the time. Maximum current speeds nearshore are about 0.5 kt

and occur in winter.

Conditions on the continental shelf in the mid-Atlantic are usually within the design capabilities of present-day cleanup technology. Actual cleanup feasibility would depend on weather and sea conditions at the time of a spill.

Where the mean current speed of the Gulf Stream is about 2 kt and maximum speeds are over 5 kt (see section III.A.2, Physical Oceanography), oil spill cleanup may not be possible. High seas booms are not effective in containing oil in currents faster than 1.5 kt, and oil would probably be swept under such barriers.

IV.D.

Drilling and Production Discharges in the Mid-Atlantic
Marine Environment

A listing of "typical" drilling rig (exploratory) discharges in the Mid-Atlantic is presented in Table IV.D.1-1. Also, during the production phase, approximately 233,391 gallons per day (884 m3/day) of formation waters are discharged. Of these drilling and production discharges, routinely generated and released during OCS exploration and development for oil and gas, those of primary environmental concern are the drilling muds and cuttings and formation waters; discharges of domestic and sanitary waters and deck drainage are less significant. The other discharges, as listed in Table IV.D.1-1 (including water distillation discharge, blowout prevention fluid, boiler blowdown, firewater system discharge, non-contact cooling water, ballast water, and cementing unit and washdown drain discharges), present relatively minimal environmental impact concern. All of these discharges would occur offshore.

The discharge of effluents is subject to EPA National Pollutant Discharge Elimination System (NPDES) permit regulations which require the application of "Best Practicable Control Technology Currently Available (BPT)," as specified under Section 301(b)(1)(A) of the Clean Water Act, and effluent limitations found at 40 CFR 435 (Oil and Gas Extraction Point Source Category) and 40 CFR 125 (Ocean Discharge Criteria) or, if ocean dumped, at 40 CFR 227-228 (July 1, 1983). According to EPA's Ocean Discharge Criteria, compliance means no "irreparable harm" would result to the marine environment.

Drilling muds are complex chemical mixtures which are circulated through the well bore during drilling. Drill cuttings are those rock particles displaced during drilling. Drilling muds (fluids) cool and lubricate the drill bit and drill pipe, transport drill cuttings to the surface and maintain them in suspension should circulation be interrupted, provide hydrostatic pressures to counteract formation pressures and thereby prevent blowouts, and support part of the drill bit and string weight.

The quantities and properties of both muds and cuttings discharged depend on the well depth, hole size, geologic formation encountered, mud dispersability, and solids control capacity.

During drilling operations, drilling mud is circulated down the well hole through the drill pipe, picking up drill cuttings, and returned to the surface. There, the cuttings and mud are separated, the cuttings discharged to the ocean, and the mud recirculated. Drill cuttings are discharged continously during drilling operations. The bulk of the discharge cuttings occurs for the 0 to 5,000 foot depth zone (usually the first third of the program). With increasing well depth there is a decrease in the volume of cuttings per foot because the size of the drill bit decreases, so that during the last third of drilling there are very small amounts of drill cuttings discharged (Petrazzuolo, 1981).