To select a sample of the waste and prepare it for chemical extraction and analysis, there are three required levels of random sampling.
(a) First, select a single 19-liter (5 gallon) portion from a composite accumulated either contemporaneously with the generation of the waste or by sampling an existing pile of waste. Collection procedures for the first level of sampling from existing piles of waste are in Sec. 761.347. Collection procedures for the first level of sampling from a contemporaneous generation of waste are in Sec. 761.348. Compositing requirements and requirements for the subsampling of composite samples to result in a single 19-liter sample are in Sec. 761.350. Send the 19-liter sample to the laboratory for the second and third levels of sampling, including particle size reduction for leach testing and drying as required by Sec. 761.1(b)(4).
(b) Second, at the laboratory, select one quarter of the 19-liter sample. Procedures the laboratory must use for this second level of sample selection appear in Sec. 761.353.
(c) Third, select a 100 gram subsample from the second level subsample. Procedures the laboratory must use for this third level of sample selection appear in Sec. 761.355.