Application of the American Society of Testing and Materials’ (ASTM) New Skimmer Test Protocol
The American Society of Testing and Materials (ASTM) subcommittee on skimmers recently adopted a standard methodology for measuring the nameplate capacity for a given skimmer system. Current industry practice allows manufacturers to label skimmers with a nameplate capacity that may bear little relationship to the ability of the skimmer, as a system, to recover oil. Manufacturers frequently base nameplate capacity solely on the skimmer’s offload pump capability. Typically, this value is unrealistic when estimating the oil recovery rate (ORR) of a skimming system. In the absence of verifiable third party data or USCG witnessed testing in accordance with 33 CFR 155 Section 6, the USCG will derate manufacturer’s claimed nameplate capacity by 80% or more when calculating the Effective Daily Recovery Capacity (EDRC). The USCG uses EDRC as a key component in rating and regulating the oil spill response capability of responsible parties and oil spill removal organizations (OSROs).
In March 2008, the new skimmer test protocol was used at Ohmsett to test four oleophilic skimmers and evaluate their potential use as alternatives to the skimmers currently used in the Prince William Sound (PWS) oil spill response plan. The skimmers currently used in the PWS plan are weir-type devices, which generally have low recovery efficiencies, i.e., they recover substantial volumes of water along with the oil. This can add greatly to the storage requirement, which is logistically complex and costly. It is anticipated that oleophilic devices would offer an advantage because of their generally higher recovery efficiencies.
These tests were intended to provide a comparison between four different skimmers in conditions that replicate fresh oil and the 72-hour oil spill cleanup scenarios mandated by the state of Alaska. This test initiated the first real-world application of ASTM’s new skimmer test protocol.