M4L9Chain

Module IV

Lesson Nine: Stormwater Sampling Procedures

Chain-of-Custody (COC) Procedures

The Chain-of-Custody (COC) refers to the documented account of changes in possession that occur for a particular sample or set of samples. The COC record allows an accurate step-by-step recreation of the sampling path, from origin through analysis. With the COC documentation, the permittee can have confidence that their samples are not tampered and are representative of a specific site’s stormwater runoff. Information includes in the COC:

Name of the persons collecting the sample
Sample's ID number
Date and time of the sample collection
Location of the sample collection
Names and signature of all persons handling the samples in the field and in the laboratory

Usually the COC form needs to be developed to include all information listed above and is printed on carbonless, multipart paper so all personnel handling the sample receive a copy. When transferring possession of samples, the transferee should sign and record the date and time in the appropriate section of on the COC record. All sample shipments should be accomplished by the COC record and a copy of these forms should be retained by the originator. In addition, all receipts associated with the shipment should be retained. Only the sample collectors will sign the COC form over to the lab. COC procedures will be strictly adhered to for quality assurance/quality control (QA/QC) purposes.

Click here for a sample of the chain-of-custody form.