ARCHIVED REPORTS_XR0006765 - Laserfiche WebLink

Home Browse Search

ORC TECHNICAL BULLETIN # 1.2d Oxygen Release Compound,ORC® Alaska Field Results RECENESIS made its first sale to the Anchorage office of Hart-Crowser for implementation in Homer, Alaska The site was a utility company property that had experienced significant hydrocarbon releases from tanks and pipelines The dissolved phase was present in a shallow water table characterized by a coarse gravel This gave the site a very high flow characteristic - possibly in excess of 40 feet a day during time of maximum flow At the other extreme there was a dramatic reduction in flow throughout the winter freeze cycle The unproven nature of the technology led to the suggestion of a pilot test, and at the same time,afforded the opportunity to make a comparative study against air sparging The primary objective was to observe the extent of oxygen dispersivity with some attention placed on BTEX remediation The experimental design is presented as Figure 1, Tables i and 2 present the data Attempts to use air sparging failed because the sparge points fouled in the high iron environment and there was evidence of channeling The results were impressive enough to warrant the purchase and _ installation of a full Oxygen Barrier. The layout of the site and the barrier system is presented in Figure 2. Although the test period was taking place during a period that included the freeze cycle, there was enough activity and measurements made during the thaw cycles on either side of the freeze, to show the barrier could reduce BTEX and TPH. In April, 1995, four months after installation, the following was recorded. At MW-5 which is the furthest downgradient point before the road (that Hart-Crowser believes had yet to be traversed by flow), benzene was reduced from 320 ppb to 9.8 ppb and total BTEX went from 1361 ppb to 17 ppb. Gasoline range organics went to ND from 7.4 ppm. Diesel range organics rose from ND to .55 ppm, indicating there may have actually been a rise in background conditions during the course of operations It is useful to note that the barrier was charged with the old, less active ORC-concrete formulation. The barrier was recharged in July with the current product that is packed in filter socks. Another round of data was collected in August about a month after installation The results are presented in Figure 3 It is believed that after the thaw the recharge was