Health Assessment for Union Pacific Railroad Yard-Pocatello Sludge Pit, Pocatello, Idaho, Region 10. CERCLIS No. IDD055030852

摘要

The Pocatello Sludge Pit site is on the National Priorities List. From 1961 until 1983, Union Pacific dumped sludge from its oil/water separation plant into this unlined pit. The sludge/soil material was found to be contaminated with heavy metals (cadmium, 20 ppm; lead, 1,460 ppm; chromium, 105 ppm; arsenic, 20 ppm; zinc, 1,530 ppm; and mercury, 0.1 ppm) and organic solvents (ethylbenzene, 100 ppm; methylene chloride, 86 ppm; and 2-methylnaphthalene (2,600 ppm). Groundwater contamination of the upper aquifer underlying the site may have occurred. Private drinking water wells have been found to be contaminated with tetrachloroethylene (9.5 ppb), 1,2-trans-dichloroethylene (17 ppb), and trichloroethylene (16 ppb). The site is considered to be of potential public health concern because of the risk to human health caused by the possibility of exposure to hazardous substances via groundwater and possibly air.