Containers

Building a kit

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Start from the analyte list Then the shortest holding time Count containers per site, then add spares Spare closures too Label everything before leaving On the container, never the lid Pre-chill the cooler Keep ice off the glass Separate the clean from the used And put the card in the lid of the cooler References

The kit is planned backwards, from the laboratory's opening hours to the bag.

Start from the analyte list

Every container in the kit exists because a row in the table asked for it. A kit assembled from what looked useful is a kit with the wrong materials in it.

Then the shortest holding time

It governs the trip. One 8 hour bacterial parameter turns a leisurely day into a route planned around a laboratory counter.

Count containers per site, then add spares

A dropped bottle at the third site of five ends the day. Spares weigh almost nothing and are the cheapest insurance in field work.

Spare closures too

409 closures on this shelf against 359 containers. A cap lost in a stream is a sample that cannot be closed, and a cap is lighter than a bottle.

Label everything before leaving

Wet hands, cold fingers and a marker do not combine. Pre-labelled containers with site and parameter already on them leave only the time to be written.

On the container, never the lid

Lids get swapped during filling. The identity has to be on the thing holding the sample.

Pre-chill the cooler

A cooler that starts at air temperature spends the morning getting cold instead of keeping samples cold. Most rows want 6 degrees C or below and the clock starts at collection.

Keep ice off the glass

Direct contact between ice and a full glass bottle is how they break, and a full bottle has nowhere to expand if it freezes.

Separate the clean from the used

An empty labelled container and a filled one in the same bag is how a duplicate gets created and a site gets missed. Two bags, one direction of travel.

And put the card in the lid of the cooler

Analyte, letter, material, preservation, holding time, for the parameters you actually sample. It is the thing that answers a question at the water instead of in the car park.

References

The Davis Pack Supply catalog, measured 19 October 2026. The field sampling shelf is 768 rows: 359 containers and 409 closures. 5 mL to 950 mL with a median of 118; 124 containers at 60 mL or under, 211 at 120 or under, 317 at 500 or under, and nothing above a litre. 146 PET, 108 glass, 92 HDPE, 13 PP, no LDPE and no fluoropolymer. 194 jars, 163 bottles, 2 tubes. 103 clear, 82 white, 52 amber, 34 natural. Closures: 346 continuous thread, 27 dome lids, 14 phenolic, 11 liners and sealing discs, 6 specialty.

40 CFR 136.3, Table II, selected rows. Oil and grease: G, cool to 6 degrees C or below and acidify to pH below 2, 28 days. Phenols: G, 28 days. Phosphorus (elemental): G, 48 hours. Fluoride: P, no preservation required, 28 days. Silica: P or Quartz, 28 days. Boron: P, FP, or Quartz, nitric acid to pH below 2, 6 months. Cryptosporidium and Giardia: LDPE with field filtration, 1 to 10 degrees C, 96 hours. Dissolved oxygen by probe: G, bottle and top, analyze within 15 minutes. Chlorine, total residual: P, G, analyze within 15 minutes. pH: P, FP, G, analyze within 15 minutes. Coliform and E. coli: PA, G, 8 hours. Hardness: P, FP, G, 6 months. Nitrate: P, FP, G, 48 hours. ecfr.gov

Written from 40 CFR 136.3 Table II and from the catalog as it stood on 19 October 2026. Part 136 governs Clean Water Act compliance monitoring; it is used here for everything else as the best available statement of what a container does to a water sample, not as a rule that binds a student with a creek. Nothing on this shelf is sold precleaned or certified for regulated sampling, and no preservation chemistry is given, because that belongs to the laboratory running the analysis.