The Lower Passaic River Study area is part of the Diamond Shamrock Superfund site. At all Superfund sites, a document called a "Remedial Investigation/Feasibility Study" (RI/FS) is produced. The "RI" includes all study work done to understand the nature and extent of contamination and the "FS" describes potential cleanup alternatives based on that work.
Work on the RI/FS began in 2007 and is now nearing its conclusion with completion expected in 2014. In the case of the Lower Passaic, thousands of sediment, tissue and water samples have been collected as part of this process.
Preliminary findings from the RI/FS show that dioxin from the Diamond Shamrock site in Newark is the primary risk driver for sediment in the Lower Passaic River. Without this dioxin, the Passaic River is similar to countless other urban water bodies across the country. The RI/FS has also found that dioxin from this site is not limited to the parts of the River around Newark. It has been detected throughout the River, from the mouth of Newark Bay to beyond the River Mile 10.9 removal area near Lyndhurst. Liability for addressing this dioxin rests with Occidental Chemical Corporation and its related companies, which are unaffiliated with the Lower Passaic River Study Area Cooperating Parties Group (CPG).