Collect an environmental water sample under chain of custody

Practice the EPA CLP / ISO 17025 field-sampling order. The COC header is started with site metadata before the bottle is filled, and the cooler is not relinquished without matching labels and signatures.

1. Record site ID, GPS, date, time, and weather on the field sheet.
2. Start the chain-of-custody header with sampler, site, and planned analyses.
3. Don the required gloves.
4. Do not touch the bottle lip or the inside of the cap.
5. Rinse or preserve the bottle exactly as the method requires.
6. Collect at the specified depth, facing upstream if surface water.
7. Cap the bottle immediately.
8. Label with the unique sample ID that matches the COC.
9. Bag or apply the custody seal.
10. Place the sample on ice.
11. Complete the COC time, preservative, and container-count entries.
12. Relinquish the cooler only to the lab courier with both signatures.