40 CFR § 761.295
Reporting and recordkeeping of the PCB concentrations in samples
June 9, 2020
(a) Report all sample concentrations for bulk PCB remediation waste and porous surfaces on a dry weight basis and as micrograms of PCBs per gram of sample (ppm by weight).
(b) Record and keep on file for 3 years the PCB concentration for each sample or composite sample.