CAFO Water Sampling

How To...

Conduct Water Sampling Near a CAFO

A volunteer reaches down from atop a culvert to take a water sample from a stream.

If you see or suspect a CAFO pollution discharge, you need to conduct tests of the water.

Water sampling is very rewarding. By taking samples you are collecting evidence that there is a problem. You are guarding the water for future generations.

A. Why You Should Sample Water
B. What to Sample For, How to Sample
C. MDEQ-Approved Labs

A. Why You Should Sample Water

Environmental protection agencies don't typically rely on citizen water or air test results for enforcement purposes. So, why should an average citizen conduct water sampling near a CAFO?

Water testing by citizens is valuable because it documents potential pollution problems. CAFO designs allow manure, silage leachate, milkhouse wastes or other pollutants to enter surface waters of the state at one time or another. Most CAFOs have production areas, lagoons, barns, silage bunkers or other facilities too close to surface waters. Inlets are built too close to field tiles and other conveyances to state surface waters.

Through good water-sampling technique, thorough documentation and quality-controlled accurate results, you build credibility, which in turn helps convince agency staff that you are an ally in their enforcement of water quality standards.

When water sampling, always remember:

Follow the proper protocol
If you live in Michigan, refer to the collection of evidence protocol by the Michigan Department of Environmental Quality. If you live elsewhere, find comparable criteria for collecting evidence in your state. The main points are to use clean sterile collection bottles and getting the sample from the middle of the water column if that's possible. DEQ wants three samples in one bottle, from left bank, right bank, and mid-stream, if possible.

Don't be fooled
Even an obvious discharge of manure at a CAFO does not necessarily mean a water quality violation has occurred. In Michigan, for example, a violation hasn't occurred unless a discharge causes or contributes to a violation of Michigan's Water Quality Standards in waters of the state.

The goal of your water sampling is to convince state agencies to conduct complete inspections by authorized state officials. Official inspections can lead to mandates to install containment structures, to remove inlets, drainage tiles, and any other conveyances from around production areas, and to reroute surface and subsurface drains away from water. Water sampling is a crucial first step toward reducing the number of illegal discharges from production areas.

B. What to Sample For, How to Sample

Some of your water samples will go to the lab for testing, while other samples will be tested on-site with a handheld meter. 

A DO test is done on-site. Conduct this test both upstream (if possible) and at the site of concern. Write down the reading on the DO meter as well as photograph the meter reading, holding it so that the source of the water you just tested is visible in the background. This will document both the reading, and the location of your test.

E. coli must be tested off-site, meaning that you'll bring properly collected water samples to the lab.  You may choose to have the nutrients tested off-site, or you may use test strips for orthophosphate, nitrates/nitrites, and ammonia.

All water samples must be collected in sterile bottles, following strict collection protocol. These samples should be delivered to an MDEQ certified lab within four hours (see below). While en route, store your samples in a cooler, on ice, observing the limited holding time.

C. MDEQ-Approved Microbiology Labs

Read the statement on the Michigan Department of Environmental Quality's drinking water webpage. Through the MDEQ drinking water website, you'll find:

  • information on fees (if you use the MDEQ's labs)
  • a directory of microbiology labs and/or drinking water labs around the state
  • information on interpreting test results

MDEQ will process samples from surface waters, as well as drinking water.

  • There may be more than one lab in your area, so call to compare fees, procedures, and hours of operation.
  • Labs may supply you with sterile sample bottles. Often when you drop off samples to process, they'll supply you with new, sterile bottles.
  • Call ahead. Many labs are city or township drinking water labs. These open early in the morning and may not be open late in the afternoon. It's important to call ahead. Let the lab know you will be bringing them samples that day. Ask them how late they'll be able to accept your samples.
  • Do not show up with samples only minutes before closing. This is especially true if asking them to process samples for E. coli bacteria, which has a total "holding time" of six hours, part of which the lab needs in order to process the sample.

Next, organize community members to Stop a CAFO