The American Society of Testing and Materials (ASTM) subcommittee on skimmers recently adopted a standard methodology for measuring skimmer performance, F 2709 - . Standard Test Method for Determining Nameplate Recovery Rate of Stationary Oil Skimmer Systems. Current industry practice allows manufacturers to label skimmers with a nameplate capacity based solely on the skimmer’s offload pump capability without regard to the recovery rate as a system. Additionally, there is no consideration given to the degradation in recovery performance when pumping fluids with viscosities higher than water. Typically, the manufacturer’s claimed value is unrealistic when estimating the oil recovery rate (ORR) of a skimming system. Integrating actual performance data into the planning and regulation process is prudent from all perspectives. In the absence of third party data, the United States Coast Guard (USCG) will de-rate a 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 response organizations (OSROs).
The ASTM’s new skimmer protocol has been used recently at Ohmsett to evaluate four oleophilic skimmers as potential alternatives to the skimmers currently used in Alaska’s Prince William Sound (PWS) oil spill response plan. The selected skimmer has undergone a number of modifications with improvements quantified over four additional tests series. This paper focuses on the most recent test of this skimmer, conducted in cold-water conditions using both fresh and weathered Alaska North Slope (ANS) crude oil. During the latest testing, two newly introduced tests were performed: a 24-hour endurance test and a qualitative recovery test in the presence of seaweed.
Use of the newly developed ASTM Standard F 2709 (Standard Test Method for determining nameplate recovery rate of stationary oil skimmer systems)