A judicial review does not stop a sample bottle from needing a label. When a drinking water standard is challenged in court, the regulatory text may be argued at length while the operator's sampling program keeps running, and the records that program produces are the ones that will be examined later, whichever way the case is resolved. For PFAS work, where target compounds are measured at very low concentrations and field equipment can itself be a contamination path, the gap between the legal question and the field practice deserves attention now.
The current case shows why. Water Finance and Management reported on oral arguments in a judicial review, heard by a three-judge panel of the D.C. Circuit, of the EPA's National Primary Drinking Water Regulation covering "six per- and polyfluoroalkyl substances." The same report notes that the EPA finalized that regulation on April 10, 2024. Oral argument is a hearing, not a decision, and the outcome could leave the standard in place, modify it, or set it aside. An operator cannot know in advance which of those paths will govern its schedule, so the sampling file should be built to serve any of them.
The chain of custody is the first defensible link
A PFAS result is only as useful as the record that connects it to a specific sample. That record should identify the sample, the collector, the date and time, the exact location, the container type, any preservative, the transport conditions, the receiving laboratory, and the time of receipt. Each handoff needs a signature or an electronic equivalent. The laboratory's written instructions govern the specific containers, preservatives, and holding times for each analyte, and those instructions belong in the sampling file rather than in the memory of the crew that collected the samples.
Field conditions add their own failure modes. Sampling gear, tubing, gloves, and clothing can introduce compounds that the crew does not expect, and the lab's guidance usually specifies which materials to avoid. A crew that is trained on the procedure but not on the reasons behind it will tend to drift from it under time pressure, and that drift is hard to detect after the fact unless the records show what was used on each day.
Blanks separate a finding from a artifact
Field blanks, equipment blanks, and travel blanks exist to detect contamination introduced during collection, handling, or transport. Their value is comparative. If a blank carries a detectable signal, a reviewer can ask whether a sample result reflects the source water or the sampling process. Without blanks, a detected result cannot be separated from a contaminated one, and a nondetect cannot be trusted to mean absence.
The tradeoff is cost and handling time. Additional blanks add analytical charges, consume bottles, and lengthen the field day. Those costs are real, and a utility with a limited budget may be tempted to cut them. The argument for keeping them is that the cost is small relative to the cost of disputing a result after it has been reported, and that the blanks are often the only evidence that answers the question a reviewer will eventually ask.
Keep the file in the form a reviewer would need
The sampling file should be complete enough that someone who was not present can reconstruct each event. That means retaining field logs, signed custody forms for every transfer, full laboratory reports including qualifiers and method details, calibration records for any field instruments, and a note of which regulatory version the utility was applying on each sampling date. If a standard is later revised or vacated, historical data can then be reconciled against the requirements that were in force when the samples were taken, rather than against whatever requirement is in force at the time of the review.
Storage is the usual objection. Retaining paper and electronic records for longer periods takes space and staff time, and records kept on individual personal drives are easily lost when staff change. A shared, dated repository with a clear retention schedule is less expensive over time than rebuilding a file from partial notes.
Questions to settle before the next round
Before the next sampling round, the utility should be able to answer several questions in writing. Who signs each custody transfer, and what happens when the signer is absent? Does the laboratory's holding time match the sampling calendar, including weekends and transport delays? Are blanks scheduled for every batch, or only when someone remembers? Where are the records stored, and who can retrieve them five years from now? Questions about the legal status of the rule itself belong with counsel and with the state agency that holds primacy, and they should be tracked on their own record. The sampling file, however, is the operator's own responsibility, and it does not wait for the court to finish.