What test does the EPA use to characterize lead waste if it fails the TTLC?

The correct answer, the Toxicity Characteristic Leaching Procedure (TCLP), is used by the Environmental Protection Agency (EPA) to determine if a waste material contains hazardous levels of lead. When waste fails the Total Threshold Limit Concentration (TTLC), which establishes a threshold for the total amount of a hazardous substance present in the waste, it signals that further testing is necessary to evaluate its potential for leaching.

The TCLP is specifically designed to simulate the leaching that occurs in landfills and helps assess the potential for toxic contaminants to leach into groundwater. This procedure involves extracting the waste with a specific leachate solution and subsequently analyzing the leachate for the presence of lead and other hazardous substances. If the concentration exceeds the regulatory limits, the waste is classified as hazardous.

The other options provided, such as STLC (Soluble Threshold Limit Concentration) and MUC (Maximum Use Concentration), are not standard methods used by the EPA for this purpose. The TTLC itself is a screening tool rather than a method for characterizing the waste after it has been identified as problematic. Thus, TCLP is the appropriate test to characterize lead waste after it has failed the TTLC.