This paper describes the design, fabrication and test of a prototype system for the recovery of spilled oil from the surface of river, estuarine and harbor waters. The system uses an open cell polyurethane foam, in the form of small cubes, to absorb the floating oil. The system is highly mobile and is capable of being transported in two pickup trucks. The sorbent is distributed onto the oil slick by means of a pneumatic broadcaster. An inclined, open wire-mesh belt conveyor is used to remove the saturated sorbent from the water. The recovered oil and water are removed from the sorbent by squeezing in a converging belt press, or regenerator. After regeneration, the foam is reapplied to the oil slick. The foam is capable of being reused for more than 100 cycles. Tests of the system, using both diesel fuel and lubricating oil, were conducted at the Environmental Protection Agency's OHMSETT test tank. The sweep speeds ranged up to five knots in both calm water and in waves. System throughput efficiencies ranged from 45% to nearly 100%. Oil collection rates of up to 2,300 gal/hour were achieved. The oil content of the recovered liquid varied from 38% to 79%.

In June of 1971, EPA awarded five research contracts designed to develop efficient unit operations for the removal of floating oil with the aid of sorbent materials. Each contract considered the following basic unit operations:Sorbent BroadcastingOil-Sorbent HarvestingOil-Sorbent SeparationVessel or Platform ConfigurationOil Storage or DisposalSorbent Reuse and/or Disposal Of the five contracts awarded, one involved the utilization of material handling systems for oil recovery use, one consisted of a study optimizing the broadcasting and harvesting of sorbents, one involved the in situ generation of foamed sorbent material, and two involved the use of specially designed platforms for the unit operations under consideration. Analysis of the research results indicate that mechanical sorbent systems can be used efficiently and effectively to recover spilled oil Recovery efficiencies better than 90 percent can be expected. Within design limitations, wave action will have little effect on oil-sorbent recovery. In practice, wave action actually increases oil removal rates by bringing the oil into more intimate contact with the sorbent. Wind will produce detrimental effects on the broadcasting unit operation. However, these effects can be minimized by proper field operating techniques. This paper evaluates the unit operations developed by the five contractors and discusses the additional work required for prototype system development.

In high current oil spill cleanup operations, containment devices should be used as one element in a containment-pickup system. To achieve successful control over the oil slick, three activities have been identified based on an analysis of the present hydrodynamic theory of oil spill containment:absorb or convert the kinetic energy of the fast-flowing water streamseparate the oil film from as much of the free-flowing stream as possibledirect the oil film to a controlled area to facilitate its collection and removal. Acting under the authority of the Federal Water Pollution Control Act Amendments of 1972, the Environmental Protection Agency awarded a contract to Ultrasystems, Inc., of Newport Beach, California, to design, develop, and demonstrate a streamlined boom utilizing hydrofoil concepts. Additionally, EPA awarded a contract to the Shell Development Company to develop an unconventional boom profile utilizing a perforated incline plate as a baffle upstream of a conventional plate boom. This baffle creates a flow-sheltered region where the oil layer can thicken, thus facilitating its removal. Following developmental tests of these concepts, full-scale prototype tests will be conducted at the Environmental Protection Agency's OHMSETT facility in Leonardo, New Jersey. Following these tests, final reports will be issued which will include recommended design, fabrication, and material specifications.

As environmentalists, we must constantly be aware of, and recognize the potential pollution problems that might result from an oil spill cleanup approach or system. Based on biodegradability and ultimate oxygen demand data developed by the Edison Water Quality Laboratory as well as others, it would appear that more than knowledge of toxicity and emulsion efficiency should guide our decisions regarding the use of chemical dispersants for oil spill cleanup.

When compared on an individual basis to major oil pollution disasters, the average Navy oil spillage incident seems insignificant. However, when the cleanup costs are tallied, these limited oil spills do not appear so small. For example, a one barrel oil spill, discharged from a destroyer berthed at the Long Beach Naval Shipyard, took nine laborers, a boat operator, a truck driver, a crane operator and a supervisor one and a half days to clean up at a cost of $1,300. On the East Coast, the Norfolk Naval Shipyard spends approximately $1,000 an incident in its oil spill cleanup operations. These spills vary between 50 and 500 gallons. From the presented data which defines the limited oil spill, three general statements are derived:1. Limited oil spills are a large problem due to their numerous occurrences.2. Limited oil spills require proper treatment.3. Limited oil spills are expensive to treat. This paper investigates this last statement and by so doing discloses the actual problems which contribute to the high cost of cleaning up limited oil spills. Three factors are discussed:1. The physical conditions affecting an oil spill.,a. Location of the slick,b. Oil Slick Movement,(1) Spreading,(2) Weather, wind and current effects,2. The type of equipment employed.,a. Booms,b. Chemical Dispersants,c. Physical Removal,(1) Skimmers,(2) Straws,3. The completeness of the removal operation. The limited harbor oil spill is expensive and the cost is expected to rise. At the present time, the typical oil spill costs the Navy over $1,000 to clean up. This cost will increase as control agencies rightfully require more removal and more complete removal.