Commander William E. Lehr United States Coast Guard, Washington, D.C.
Besides enforcing federal antipollution laws on U.S. navigable waters, the Coast Guard is also conducting R&D programs
Coast Guard activities in pollution control
P
olluting inland waters, estuaries, and oceans through deliberate and accidental discharges of foreign materials has been a matter of concern for many years. In the United States, the first water pollution legislation, the New York Harbor Act, was enacted in 1886. However, wide public awareness and concern for environmental pollution in general, and water pollution in particular, are rather recent occurrences. During the past few years events such as the oil platform accident and the various tankship catastrophes have dramatized the detrimental effects of major accidental pollutant releases. Similarly, the discovery of marine animal contamination with DDT and mercury illustrated the dangers inherent in chronic, deliberate discharges of supposedly innocuous foreign materials. For its part, the U.S. Coast Guard has been involved with federal water pollution activity for over 50 years. This interest is a natural one since several of the Coast Guard’s statutory responsibilities bear directly or indirectly on water pollution abatement. The Coast Guard is the maritime law enforcement arm of the government. As such, it’s responsibilities include enforcing federal antipollution laws on the navigable waters of the United States. Typical of such statutes are the Water Quality Improvement Act of 1970 and the Refuse Act of 1899. The Water Quality Improvement Act is of particular interest, giving the Coast Guard additional responsibilities regarding reporting and cleaning up pollutant spills and certifying marine sanitation devices. 512 Environmental Science & Technology
The Coast Guard is also responsible for implementing general vessel safety statutes and maintaining the maritime aids to navigation system, While these responsibilities are not directly related to antipollution activity, they do have an impact on pollution prevention. Properly used aids to navigation systems and safely constructed vessels should result in fewer accidents. Fewer accidents, in turn, mean fewer pollutant spill incidents. From a different point of view, the Coast Guard has a deep internal interest in vessel pollution. As the operator of a major fleet of boats and ships, it also must comply with the various antipollution regulations. Coast Guard responsibilities therefore cover the full range of prevention, control, and cleanup of water pollution. They are concerned with all potential and (or) actual forms of marine transportation-related pollution. Oil pollution, sewage wastes from vessels, and hazardous pollutants such as bulk chemicals are of particular interest to the Coast Guard. Regulations
The best method to control pollutant spills is preventing their occurrence. Activity regarding spill prevention is being carried out in several areas. One such area is directed toward achieving new regulations to inhibit spills. Activities of the Intergovernmental Maritime Consultative Organization ( IMCO) of the United Nations typify this effort. The Coast Guard is an active participant in IMCO as a U.S. representative. IMCO is presently studying the problems of casualty preven-
tion. liability, control of released oil, and pollution from industrial and other waste disposal. IMCO has also been assigned responsibility for revisions to the International Convention for the Prevention of Pollution of the seas by oil. Other efforts within the Coast Guard have been directed toward analyzing the causes of pollutant spills on navigable waters. From these studies recommendations for new regulations covering personnel training, special transfer equipment, and handling procedures are being developed. Vessel safety
Another pollution prevention area is an adjunct result of research supporting vessel safety. While this research is specifically directed toward developing improved ship construction standards and improved ship positioning systems, it furnishes an indirect benefit to pollution prevention. Recently completed research examined the potential bulk release behavior of liquefied natural gas and chlorine. This work has implications for spill control and cleanup as well as providing background data for tank sizing and structural protection for cyrogenic-liquid carrying ships. A current research project is related directly to pollution prevention in tankship accidents by examining the ability of single and double hull construction to absorb collision energy. When completed, it will provide a tool to evaluate the effectiveness of various types of hull construction to preserve cargo tank integrity and protect against cargo release.
feature
ADAPTS. The ADAPTS diesel engine in a watertight container for airdrop (below) falls during prototype field tests ( l e f t ) . The ship in the background simulates a stricken tanker
Research and development supporting ship positioning systems has been conducted for many years. The results of this past work are reflected in the existing electronic navigational aids and the channel marking biioyage system. The objective of present research is to improve these systems. New and (or) improved light sources for navigational buoys are under investigation, In addition, an analog model for investigating harbor traffic patterns as a function of channel marker position, ship characteristics such as speed and turning response times, traffic density, and local weather has been developed. The model will determine the need for repositioning harbor navigational aids to assist the safe navigation of modern ships. A particularly important project is also being conducted in harbor traffic information, demonstrating the feasibility of Harbor Advisory Radar (HAR) services for U.S. ports. Shore-based radars have been utilized in certain European ports since 1946. Experience there has indicated that harbor radars are useful in reducing collisions and assisting in traffic movement during periods of poor visibility. Assessing the feasibility of harbor advisory radar began in January 1970 with activating an experimental system in San Francisco. The first phase of the experiment, now nearing completion, has four objectives: * Determining US. mariner acceptance of shore-based advisory services; Determining manpower and training requirements for HAR operators; * Providing an economic analysis of HAR concepts in regard to system
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Volume 5, Number 6, June 1971 513
R&D funding in Oil Pollution Abatement (dollars in thousands) costs and benefits resulting from reductions in delays of harbor transits; Investigating the capability of WAR services to meet present and future navigational requirements of U.S. ports (in terms of collision and delay avoidance, search and rescue, and law enforcement). Preliminary phase one results indicate widespread acceptance by mariners. In fact, intraharbor vessels that did not previously report to the Vessel Movement Reporting System are now reporting to the HAR center. Although too soon to report on the economic aspects of HAR and its collision avoidance capability, the preliminary results are, however, encouraging enough to warrant initiating the experiment's second phase.
514 Environmental Science & Technology
FY70
291 84
579 2,011 662 345
FY71
FY72"
Oil pollution control
ADAPTS Containment systems Oil harvesting Law enforcement/surveillance Total Total appropriation for m a r i t i m e pollution R&D
...
...
I . .
500
700 1,100
800
1,000
1,000
159
-
-_
-
534
3,597
2,800
2,300
804
4,288
4,000
6,700
,~
A m o u n t r e q u e s t e d in t h e President's Budget.
As part of sensor system research, a special interim photographic comparison manual has been produced. This manual is designed to assist aircraft crews in identifying violators of the current 100 parts per million and (or) future 60 liters per mile oil discharge limits.
Law enforcement
For many years routine surveillance patrols have been conducted to detect violators of the antioil pollution statutes. These patrols utilized visual sighting to determine pollution incidents. Unfortunately, dependence on visual sightings restricted effective surveillance to clear weather, daylight operations. In order to improve detection capability, a research and development project has been established to produce an all-weather, airborne surveillance system which could detect, map, and measure the film thickness of an oil slick. Since summer 1968, research has been directed toward defining optical properties of oil slicks and determining the ability of various sensor techniques to detect oil on the ocean surface. During this period, opportune spills such as the SS Arrow spill in Nova Scotia and the Chevron platform fire, as well as a series of controlled test spills, have been used to obtain data on sensor capabilities. Typical sensors operating in the ultraviolet, visible, infrared, and microwave regions of the electromagnetic spectrum have been tested. The past work results are now being analyzed. The analysis is considering aircraft capabilities, operational requirements, and sensor capabilities to define the best sensor package to meet objectives. When the analysis is completed, a prototype surveillance system will be constructed.
FY69
Shipboard equipment
All vessels can produce minor pollutant discharges as part of their normal operations. The most common are sanitary waste discharges and excess oil in bilge and ballast water. Developing seagoing sewage treatment systems is the oldest project in the Coast Guard R&D program. Its overall objective is to provide devices which adequately treat sanitary wastes in Coast Guard vessels. Three sizes of waste treatment systems, identified to meet these needs, include a ship system capable of handling the waste discharges from 50 men; an intermediate, 10 to 20-man system for use in smaller manned vessels: and a treatment device for use onboard intermittently manned patrol boats. General requirements for all systems include: Systems must be self-contained package units which include all special support equipment except electric power. The overall size and weight of treatment systems should be minimized. Equipment must be simple to operate and not require full time attention by specially trained operators. Equipment reliability must be emphasized so that routine maintenance will be at a minimum. Further, individual system components should be sized to facilitate installation
through typical existing access doors and hatches. Systems must offer complete treatment as required by law. The R&D program began in the early 1960's with shipboard test and evaluation of several commercially developed ship treatment plants that were marinized versions of land-based package treatment devices. In 1965, development of a sewage treatment system specifically designed for shipboard use was undertaken. The resulting treatment plant was based on the aerobic digestion process and represented a significant improvement over the previously tested marinized devices. Unfortunately, it did not meet all of the design goals or performance requirements. At the present time, two new treatment plants are being developed. Both are concentrating on solid/liquid separation techniques. One plant will use a centrifugal separation scheme. The other will utilize ultrafiltration (membrane separation) to effect separation. Both plan to remove solid material and dispose of it by incineration. The relatively pollutant-free liquid which makes up the bulk of sanitary wastes will then be treated in a disinfection process and pumped overboard. A fullsize prototype is scheduled to be available for shore test and evaluation within six months. Oil spill control
Notwithstanding the best prevention efforts, occasional massive pollutant spills will still occur. Mechanical failure or human error will continue to cause maritime disasters. Thus, whether due to a ship casualty or oil platform accident, specialized techniques and equipment will be needed to combat massive spills at sea.
The lack of cleanup methods for large oil spills was first demonstrated by the SS Torey Canyon accident in 1967 and the breakup of SS Ocean Eagle in San Juan Harbor in 1968. In both incidents cleanup could only be effected when the oil came ashore. By that time widespread disfigurement of recreational areas and destruction of marine life and birds had occurred. Additionally, restoration of the shoreline proved to be costly and time consuming. The ability to combat oil spills at their source (at sea) could have eliminated those problems.
If the intact cargo could have been removed, subsequent spills could have been significantly reduced. Unfortunately, most accidents seem to occur in either shoal water with relatively severe weather, or locations remote from empty ships and barges that might be used to receive the intact cargo oil. Development of an emergency system facilitating removal of intact cargo was the first research project undertaken. It has resulted in the Air Delivered Anti Pollution Transfer System (ADAPTS). The ADAPTS project was initiated in
Arctic oil spills. This oil spread tesi near Pi. Barrow, Alaska, helps scientisis understand oil spread in ice. 90% of the oils was removed
A high seas cleanup capability has been a major objective of Coast Guard RBD for the past several years. Fund levels for this activity are shown in the table. Past and current effort is centered on developing seagoing mechanical systems to: * Reduce oil quantities that may he released during tankship accidents; 'Contain the spread of spilled oil in relatively thick films which will facilitate recovery operations; * Harvest spilled oil from the ocean surface.
the spring of 1968. The design goals for the project specified a system to: Perform effectively in 40-mph winds and 12-foot seas; Be suitable for air delivery at the spill site within four hours of notification of an accident; * B e suitable for deployment and operation without using surface craft; * Be complete and not require support from a damaged ship; * Transfer and store 20,000 tons of crude oil within a 20-hour period. As developed, ADAPTS consists of three subsystems which are transfer pumping, temporary storage, and air delivery. The transfer pumping subsystem has two major components. One is a two-stage centrifugal pump driven by a close coupled hydraulic
motor, This unit is 12 inches in outside diameter, 9 feet long, and can be lowered through a Butterworth fitting. It weighs 950 Ib when packaged for an air drop. Motive power for the transfer pump is provided by a 40-hp lightweight diesel engine driving a hydraulic pump (page 513). The packaged engine unit weighs 1150 Ih. The key components of ADAPTS are collapsible, 500-ton temporary storage containers. Two different styles of containers have been developed for comparison purposes. One is made of rubberized nylon and has overall dimensions of 135 feet long, 35 feet wide, and 6 feet deep. It weighs 13,000 Ib when rigged for air drop. The other container is fabricated of nylon reinforced polyurethane and is roughly
Reducing releases
Apparent from past tankship accidents, only a part of the cargo will be lost at the instant an accident occurs.
Volume 5, Number 6, June 1971 515
cylindrical in shape, approximately 12 feet in diameter, 173 feet long, and 8500 Ib in weight. Both containers are interchangeable for use with the other subsystems. The air delivery subsystem was developed around standard military parachutes and air delivery equipment (page 513). It was designed for use with existing Coast Guard cargo aircraft and helicopters. Spill containment
William E. Lehr is presently assigned at U S . Coast Guard Headquarters, Washington, D.C., as chief, Pollution Control Branch of the Ofice o f Research and Development. C D R Lehr, an engineering graduate (1953) of the Coast Guard Academy, received his M.S. and a Naval Engineering degree (1961) f r o m the Massachusetts Znstilute of Technology. A f t e r serving aboard Coast Guard cutters in the Pacific, Alnskan waters, and in the North Atlantic, as well as i i training positions and combat duty in South Vietnam, C D R Lehr assumed his present post in 1968. The opinions or assertions contained herein are the private ones of the writer and are not to be construed as official or reflecting the views of the Commandant or the Coast Guard at large.
A system to restrict the spread of spilled oil is a practical necessity if effective oil spill cleanup operations are to be carried out. Development of systems to contain the spread of spilled oils was begun in the spring of 1969. Since then, theoretical and laboratory research into the fluid mechanics of oil slick containment, and boom motions and stresses in current and wave fields has been completed. The results of the engineering research were applied by conducting a six-month preliminary design competition for high seas qualified oil containment barriers. The preliminary design competition was completed in June 1970 and provided in-depth proposals for subsequent design and construction of five different barrier concepts. These proposals were then subjected to a detailed technical evaluation to select the concept with the most promising performance characteristics. At the present time a prototype oil boom is being constructed and will he taken to sea for environmental testing this month. As now designed, the prototype will have a 27-inch draft and a 21-inch freeboard. It will be 1000 feet long and have provisions for anchoring. Buoyancy will be furnished by inflated, horizontal tubes spaced about 60 inches apart. The primary strength member of the barrier is an external tension line. The target performance goals for the prototype include: * Effectively containing oil slicks in 20-mph winds and 5-foot waves; * B e capable of surviving 40-mph winds and 10-foot seas; * Be adaptable for future modification to facilitate air delivery directly to the spill site. Spill recovery R&o for oil harvesting equipment is also well underway. By necessity, this
516 Environmental Science & Technology
work had to be delayed pending results from the containment barrier project. Advance data concerning barrier retention ability and general physical characteristics were needed to define adequately recovery equipment performance requirements. Preliminary studies were undertaken in December 1969, and in May 1970 engineering feasibility studies of five typical recovery concepts were initiated. The five concepts investigated were sorbent belt, rotating disk drum, vertical weir skimmer, inverted weir boom, and free-vortex oil concentrator. The feasibility studies utilized model testing in conjunction with a theory to develop parametric equations to predict the capabilities of each concept if developed to full size. The results of the studies indicated the recovery efficiency and recovery rate as well as predictions concerning power and support vessel requirements. Following the engineering feasibility studies, proposals were requested for participation in a preliminary design competition for a high seas oil harvesting system. Proposal evaluation submitted in response to that request was completed in April, and the preliminary design competition is underway. As now envisioned, the desired performance goals for a recovery system include an oil recovery rate of 2000 gallons of oil per minute in 20-mph winds and 5-foot seas. In addition to the foregoing major efforts, support research in several other areas of oil pollution is also in progress. Defining the physics of oil film spreading has been completed; field tests to determine the problems inherent to Arctic oil spills have been completed (page 515); and follow-on laboratory research has been initiated. Research into special cleanup techniques such as absorbent materials and liquid chemicals for oil slick herding is in progress. Although much still needs to be done, technical solutions for marine transportation-related water pollution problems are well on the way. In particular, the Ran progress in oil spill control and cleanup equipment, remote surveillance systems for law enforcement, shipboard sewage treatment, and Harbor Advisory Radar is most encouraging.
