Toxicity of an in situ oil shale process water to rainbow trout and fathead minnows.

An in situ oil shale process water, designated Omega-9 water, was used in flow-through bioassays with fathead minnows, rainbow trout and rainbow trout eggs. Of the two fish species, rainbow trout were more sensitive to acute exposure to Omega-9 water with 96-hour LC50 dilutions of 0.51% and 0.41% in two independent determinations. In embryo-larval studies, the length of fry from eggs hatched and maintained in 0.16% process water was significantly less than that of eggs hatched in control water. A solution of the 13 major inorganic constituents of Omega-9 water, with a 96-hour LC50 of 0.56% for rainbow trout, showed that inorganics accounted for most of the acute toxicity of Omega-9 water.