Q. Where can I find a list of thresholds for metal/chemicals to use to determine if the sludge-type waste from the triple basin collection system on our city sewer line is hazardous?
A. From your question, we infer that you have already determined that your waste is not a listed hazardous waste and that you want to determine whether your sludge exhibits the hazardous characteristic of toxicity. The toxicity contaminants and their thresholds are listed in 40 CFR 261.24 and include metals (e.g. lead), dioxins (e.g. Vinyl Chloride), pesticides (e.g. Silvex), and volatile organic compounds (VOCs) (e.g. Benzene). If you want to test your waste for characteristics of ignitability, corrosivity, or reactivity, you should review the federal regulations at, respectively, 40 CFR 261.21, CFR 261.22, and CFR 261.23. These regulations specify the properties that must be present for the waste to qualify as one of these characteristic hazardous wastes.