[en] On May 19, 2010, the Saltstone Production Facility inadvertently transferred 1800 gallons of untreated waste from the salt feed tank to Vault 4. During shut down, approximately 70 gallons of the material was left in the Saltstone hopper. A sample of the slurry in the hopper was sent to Savannah River National Laboratory (SRNL) to analyze the density, pH and the eight Resource Conservation and Recovery Act (RCRA) metals. The sample was hazardous for chromium, mercury and pH. The sample received from the Saltstone hopper was analyzed visually while obtaining sample aliquots and while the sample was allowed to settle. It was observed that the sample contains solids that settle in approximately 20 minutes (Figure 3-1). There is a floating layer on top of the supernate during settling and disperses when the sample is agitated (Figure 3-2). The untreated waste inadvertently transferred from the SFT to Vault 4 was toxic for chromium and mercury. In addition, the pH of the sample is at the regulatory limit. Visually inspecting the sample indicates solids present in the sample.