PFAS work is unusual in that the sampling train is part of the analysis. Fluoropolymers, coated papers and ordinary field habits can all put low-level PFAS into a sample that never came from the well. This is the short version of what most state QAPPs and EPA Method 1633A ask for — always defer to your own project plan.

Equipment

• No PTFE, FEP, PFA or other fluoropolymer in the wetted path. That includes thread tape, bailer check balls and tubing liners.
• Polyethylene, polypropylene, silicone and stainless steel wetted parts are the usual substitutes.
• Aqueous samples into HDPE or polypropylene bottles with unlined caps.
• Dedicated or disposable tubing per well; keep a bailer or pump assigned to one well where the plan allows.

Habits

• Powder-free nitrile gloves, changed between wells and after handling anything else.
• No waterproof or coated field books, sticky notes, or water-repellent rain gear near the sample.
• Decon with a PFAS-free water source and a laboratory detergent, and keep the rinse water documented.
• Collect the field and equipment blanks the plan calls for — they are how you defend an unexpected detection.

Where the gear lives

Our PFAS sampling collection is filtered on this basis: polyethylene bailers, HDPE and LDPE tubing, dedicated bladder pump systems, in-line filters, water level meters with PFAS-free tapes and decon supplies. Fluoropolymer components are deliberately left out of that list. For the pumping side of a low-flow event, see low-flow sampling.

Questions about a specific setup? Talk to a specialist before you mobilize — it is cheaper than a resample.