⇦ Back to Water Resource Management Home
¶ Introduction
Procedures for taking a water sample depending on the desired tests. Careless sampling prevents receiving an accurate test result.
¶ General Considerations
Cleanliness is always important when collecting any water sample. Contaminants often are present in small amounts so care must be taken to prevent anything but the water from contacting the opening, the inside of the bottle or the cap.
Collecting a timely sample and delivering it to the laboratory for analysis are also important. Some contaminants deteriorate or change form with time. Use only the proper laboratory sample container for the test desired.
It is prudent to keep a record of your water test results. The record should include the date and the test results. Comparing recent test results to previous results might show a trend and help identify a problem you may not have noticed.
Water test records often are needed for property sales. Good records help also support damage claims from chemical spills, leaks or poor management.
¶ Sampling Domestic Water Sources
For most water tests-including coliform bacteria, nitrate and other inorganic minerals - follow these steps when collecting a sample (see Figure 1):
- Select a faucet that is used regularly and does not leak, preferably from inside the house
- Do not use a swinging spout, or a garden frost-free hydrant
- Take the sample before the water goes through any treatment system. A device like a water softener or filter can be a source of contamination
- When sampling for inorganic minerals, disinfection is not necessary
- When sampling for coliform bacteria, wash your hands and remove the faucet aerator, being careful not to touch the inside of the faucet
- If the water drains from the faucet, let it dry first
- If the faucet is not used regularly, disinfect the faucet with heat or alcohol. Do not use heat on plastic or soldered screens
- Run the water at full force for at least 5 minutes to clear the line (see exception for lead below)
- Slow the flow to a stream free of bubbles and run for 2 more minutes
- Do not rinse the sample container before sampling. (Sample containers often contain preservatives required to protect the sample.)
- Hold the sample container in one hand and remove the cap with the other hand. Do not touch the opening or any interior part of the sample container or lid
- Move the container into and then out of the running stream without turning the faucet on and off
- Fill to the neck of the bottle or to the FULL mark and fasten cap securely. Make sure water on your hand does not drain into the sample
- NOTE: ServiTech Laboratories will only accept water samples for bacteria analysis if the sample is in a laboratory-provided container
¶ Figure 1. Sampling Domestic Water Sources
¶ Submitting Water Samples to the Laboratory
- Protect samples from direct sunlight and keep samples cool. Do NOT freeze samples
- Deliver samples for coliform bacteria testing early in the week, within 24 hours of collection. Samples should arrive no earlier than Monday morning and no later than Thursday morning
- It may be prudent to ship samples in a cooler or insulated container with ice or freezer packs
- Fill out sample submission forms completely and enclose with samples
¶ Sampling for Lead and Copper
Samples are best collected after the first irrigation set or cycle has been completed, preferably during the peak of the pumping season.
- Sample new wells after pipe and screens have been installed and after pumping out all water added during the drilling operation
- Allow the irrigation well to run for 1 to 2 hours before sampling
- Collect a sample from a faucet or port closest to the well. Sample from a nozzle or pipe opening if nothing is available closer to the well
- Do not collect samples while injecting fertilizer or chemicals
¶ Sampling Livestock Water Sources
Poor quality water used in livestock production may cause or aggravate health problems, cause water refusal, or may affect watering equipment and fixtures.
- It is not necessary to collect samples for routine coliform bacteria analysis, except under extreme circumstances. The coliform test is only an indicator of potential microbial contamination and not a specific test for disease diagnosis
- Collect samples from a hydrant or faucet used to fill tanks, if available
- Allow water to flow for a few minutes before sampling
- Samples can be collected from drinkers or fountains if they have been used frequently. Sampling from a hydrant or faucet is preferred
- Do not collect samples if water in the fixtures is stagnant
¶ Sampling from Lakes, Streams, Canals, or Ponds
- Remove the cap from the container
- Point the open bottle in the direction from which the water is flowing
- Tip the open top of the bottle downward at a diagonal
- Insert the inverted bottle so the top is below the water surface
- Rotate the bottle upward to fill it
- Fasten cap securely for shipping to the laboratory
¶ Figure 2. Sampling from Lakes, Streams, Canals, or Ponds
¶ Sampling Water for Organic Compounds
There are specialized procedures and specific types of sample containers required for collecting water samples to analyze petroleum hydrocarbons (e.g., gasoline, diesel fuel), synthetic organic compounds (e.g., pesticides), or volatile organic compounds (e.g., solvents). Contact the laboratory directly for instructions and proper supplies.
¶ References
Ohio Cooperative Extension Service. Bacteria in Drinking Water. Bulletin 795 Agdex 750. The Ohio State University.
Powell, M. G. 1990. Taking a Water Sample, MF-963. Kansas State Univ. Coop Ext. Serv., Manhattan KS