A compliance sample is not a sample until a lab certified by your primacy agency runs a certified drinking water method on it. A wastewater bench, a hospital clinic, or a well-meaning university lab can give you a number. That number will not close a monitoring period.

This page is how an operator picks the lab and ships the bottle so the result counts. It is not a walkthrough of a finished PFAS PDF. Ask your state for the current certified-lab list. Do not treat a national directory as the last word. This isn't legal advice.

Ask the state for the certified-lab list

Primacy agencies keep a list of laboratories certified for drinking water chemistry and microbiology. The list is method-specific. A lab can be certified for total coliform and not for VOCs. It can be certified for EPA 200.8 metals and not for EPA 524.2. Call or email the drinking water certification officer and ask for the current list for your contaminant group. Put the PWSID in the subject line so they know you are a system, not a homeowner.

Wyoming systems ask EPA Region 8. Tribal systems ask the EPA region that has primacy. Everyone else asks the state. A lab certified in a neighboring state counts only if your primacy agency says it does, in writing or on the published list.

Do not pick a lab because it is close, cheap to you, or already used by the wastewater plant. Do not pick a clinic that "does water." Drinking water certification is a separate program from wastewater NPDES work and from clinical microbiology.

Match the method number, not the contaminant nickname

The state's monitoring schedule, or the rule, names a method or a method group. The chain of custody and the report should carry that number. Common drinking water methods you will actually see:

  • Total coliform and E. coli: SM 9223 B (Colilert and similar enzyme substrate methods) is the workhorse. Some states still accept membrane filter methods. Confirm which ones are on your lab's certificate.
  • Nitrate and nitrite: EPA 300.0 or 353.2, or an equivalent method the state lists.
  • IOC metals (arsenic, lead as a water-quality metal, copper as a water-quality metal, and the rest of the 141.62 list): EPA 200.7 or 200.8. Lead and copper tap samples under the Lead and Copper Rule use the same analytical methods, in first-draw bottles the rule specifies. See the IOC MCL list and monitoring framework.
  • VOCs: EPA 524.2.
  • TTHM: EPA 524.2 or 551.1. HAA5: EPA 552.2 or 552.3.
  • PFAS: EPA 533 or 537.1 for compliance-style drinking water work, depending on what the state accepts. UCMR 5 used a defined pair of methods. Don't mix a research method into a compliance file. How to read the PDF is a different page: How to read a PFAS lab report.

If the certificate says "wastewater metals" or "SM 9222 for non-potable," stop. Ask for the drinking water certificate page that lists the method and the matrix as drinking water.

Bottles, preservative, and holding time

The lab should send a kit that matches the method. If you buy bottles at a hardware store, the sample is already in trouble. Check the kit against the method before you leave the plant:

  • Total coliform: sterile 100 mL (or the volume the method names), sodium thiosulfate if the water is chlorinated, no rinse, fill to the mark, 30-hour holding time to the start of analysis, cooler with ice.
  • Nitrate / nitrite: plastic or glass as the method allows, refrigerated, often a 48-hour hold if unpreserved. Some nitrate methods allow a longer hold with acid. Confirm with the lab before you collect. Don't acidify a nitrate bottle the way you acidify a metals bottle unless the lab said to.
  • Lead and copper tap samples: wide-mouth 1 L (or the volume the state named), no field acid, first draw after the stagnation the rule requires. The lab acidifies. Typical hold to preservation is 14 days. Don't flush the tap "to get a good sample."
  • VOCs (524.2): 40 mL glass vials, HCl, no headspace, sodium thiosulfate if chlorinated, 4 C, 14-day hold. Two or three vials per site is normal. A bubble in the vial is a reject.
  • PFAS: polypropylene or the bottle the method names. No Teflon tape, no sticky notes on the cap, no ice packs that leak into the bag. Hold times are method-specific. Follow the kit sheet.

Holding time runs from collection to the start of the method. A Friday-afternoon coliform dropped off Monday morning is often dead on arrival. Collect when the lab and the courier are running.

See exactly what your system is up against

Search by system name or PWSID and get your EPA violation history, open requirements, and upcoming deadlines in under a minute. Free, no account, no obligation.

Chain of custody is part of the sample

A result without a chain of custody is a story. The form should carry:

  • System name and PWSID.
  • Sample site ID that matches the siting plan or the monitoring schedule, not "kitchen."
  • Date and time of collection, and the collector's printed name and signature.
  • Preservative, chlorine residual if the method wants it, and whether the sample is compliance or special.
  • Relinquished / received signatures, dates, and times. A temperature on receipt for methods that require it.

If you hand the cooler to a board member to "drop off on the way," that person signs the chain. If the lab rejects the sample, the monitoring period is still open. Recollect inside the window. A reject is not a free pass.

Keep the chain, the report, and the invoice together. Chemical analyses are a ten-year keep under 40 CFR 141.33. Coliform is five. See water system record retention.

Questions to ask before you ship the first kit

  • Are you certified by my primacy agency for this drinking water method and this matrix? Send me the certificate page.
  • Will you report electronically to the state under my PWSID, or do I file the PDF?
  • What is the holding time, the bottle, and the preservative for this method?
  • What is the last courier pickup that still meets the hold?
  • What will you do if the sample is warm, bubbled, or past hold? I need a reject call the same day, not a number I can't use.
  • Who do you call on a TC+ or an acute nitrate? Give them the operator number that is actually answered.

Do not shop from a blog list of lab names. This page will not name labs or quote fees. Call the state, then call a lab on that list for the method you owe this month.

FAQ

Can I use the same lab the wastewater plant uses?

Only if that lab is separately certified for the drinking water method and matrix you need, and your primacy agency lists it. Wastewater certification does not travel. Ask for the drinking water certificate page.

The lab is certified in the next state. Can I send samples there?

Only if your primacy agency accepts that certification. Some states have reciprocity. Some do not. Get it in writing or find the lab on your state's published list before you collect.

Does a rejected sample count as a monitoring violation?

A reject is not a result. If you recollect inside the monitoring window and the second sample is analyzed in time, you can still make the period. If the window closes, you have a monitoring and reporting problem. Don't wait until the last day of the month to collect a 30-hour coliform.

Is a field test kit a certified method?

Not for compliance samples, unless the state has approved that specific kit as a drinking water method for that contaminant. Residual kits and field nitrate screens are operations tools. They do not replace the certified lab result on the schedule.

Check my system at /find-my-system.

Orevant provides compliance information tools. This page isn't legal advice. Confirm the certified-lab list, the method, and the holding time with your primacy agency and the lab on that list.