1999-06-30_REVISION - M1977342 - Laserfiche WebLink

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A A In addition, significant research has been conducted in Canada under the internationally recognized MEND program. In a mid-1990s study (Zinck, J.M., et al. 1997) of acid rock drainage (ARD) water treatment sludges from 11 sulfidic Canadian mine sites, researchers found that alkaline aged (higher solids content) or specifically produced HDS with >pH 9.5 generally are stable and "...would not generally be classified as hazardous wastes based on current leaching protocols and regulated contaminant limits." A summary of this report is located in Appendix C. It is not within the scope of this TR to conduct an exhaustive review of the literature relative to the stability of sludges produced from alkaline precipitation water treatment systems. However, it is readily evident that a significant body of published research exists that demonstrates definitively that by-product sludge from alkaline precipitation water treatment systems is environmentally stable and non-hazardous. 2.1 HDS Characterization HDS from the Henderson water treatment facility is composed of precipitated metals and gypsum. It contains no sulfides and is highly inert. Analytical results (Appendix D) from TCLP (EPA Method M1311) testing show a pH of 9.8 and only barium (0.02 mg/I) detected at a value between the MDL (0.02) and the PQL (0.06 mg/1). This HDS is very stable, alkaline, non-hazardous and non- toxic which, again, begs the question as to its classification as a "designated chemical." 2.2 Pond 1.2 Storage Facility Pond 1.2, originally designed as a mine water sedimentation pond, is located at the Henderson Mine site approximately 500 feet south southeast of the gate and approximately 600 feet north of Hoist House #1. Figure 2 is an overview digital u Aft a June 13.1999 TR.dm 7 TR d P tlx3.1999 TR