HowTo – Sampling from wells with embedded pumps [95%]

Priority: high
Updating: mature

This HowTo applies when we use the well owner’s embedded well pump. This can include irrigation wells and business wells, as well as household drinking water wells. This includes both categorical site wells and long term site wells.

The primary difference from monitor well sampling is that there is dedicated equipment in the well to bring up water to sample from. Cornell does not need to use its own pump and hose.

Change log:

When	Who	Comment
2021 03 03	sp17	First version derived from memory of household well sampling in counties.
2021 09 30	Sp17	Toward a full version for initial QAPP inclusion.
2021 10 01	Sp17	Reformatted for export in DOCX
2022 06 28	Sp17	Minor refresh. Bumped to 90%.
2022 08 18	Sp17	Minor update.
2023 04 26	Sp17	Minor update. The meter readings can be done before or after drawing the sample.
2023 05 24	Sp17	Minor update.
2023 06 15	Sp17	Convert to Markdown.

1. Objectives

Obtain representative samples from wells with embedded pumps.
Obtain field measurements from well water.
Record field data.

2. Quality assurance considerations unique to wells with embedded pumps

Let the water run to waste before drawing sample so that we have water more representative of fresh groundwater than of water standing in the well for days or longer. This is most important for intermittently used wells.
Wells that are in active use should be purged for a couple of minutes. Patience of host personnel is most important.

3. Equipment needed that is unique to wells with embedded pumps:

(See also the HowTo: Sampling road trips that covers equipment used across multiple sites of different kinds.) (Equipment is a subset of that used for sampling from monitor wells.)

4. Expendable supplies needed that are unique to wells with embedded pumps:

(See also the HowTo: Sampling road trips that covers supplies used across multiple sites of different kinds.) (Supplies are a subset of those uses for sampling from monitor wells.)

5. Steps onsite

Move supplies and equipment from vehicle to sampling location
Let the water tap run to waste at low to moderate flow for up to 5 minutes. The 5 minutes could vary if we have information suggested that it takes more or less time to stabilize. If the well is in active use, it needs the least purge time. If it has been inactive for weeks or months, it needs the longest. Inactive plumbing sometimes yields “rusty” water, indicating that a long flush will be needed.
Note site and date/time in field logbook. The timestamp is at the end of filling the sample container.
Draw water into field parameter measurement container; rinse and dump container; refill to make measurements. (This can also be done after drawing the sample.)
Make and record in field logbook meter measurements pH, temperature, specific conductance.
If not preprinted, fill in date on sample container labels before wetting them. Note: time is not always recorded on sample containers, but date is always included.
Rinse each sample container with well water, then fill to a level allowing for later freezing.

6. Field blanks - not applicable

Since we are simply filling containers using the well’s own plumbing and pump, there is no concept of a field blank for owner-pump wells.

7. Field log entries (per well per visit)

This will use a paper field logbook. The paper logbook is confidential so it can contain exact sites visited.

Record readings of pH/temperature/conductance just before or just after sample is taken.

Sample date, time and location. Record the end time of the last sample container fill as the sampling time of day.

Note any exceptional site conditions and any follow-up needed.