This episode features Marissa Schuh, a vegetable production educator with MSU Extension, and Mike Snarski, manager of Summit Laboratory out of Grand Rapids, MI. They clarify what exactly is required by the Food Safety Modernization Act in terms of water testing, and they discuss how growers can communicate with a lab in order to get what they need.
For help finding a water testing lab in your area, visit:
For a demonstration on how to take a water sample, watch this video: https://www.youtube.com/watch?v=uvjPyKKt66k&feature=youtu.be
Funding for this podcast was made possible, in part, by the Food and Drug Administration through grant PAR-16-137. The views expressed in the written materials do not necessarily reflect the official policies if the Department of Health and Human Services; nor does any mention of trade names, commercial practices or organization imply endorsement by the United States Government.
Introduction: Hello, and welcome to the Agrifood Safety Produce Bites Podcast, where we discuss all things produce safety, and dive in to the rules and regulations surrounding the Food Safety Modernization Act Produce Safety Rule.
Marissa: My name is Marissa Schuh, and I'm a vegetable production educator with Michigan State University Extension.
Mike: My name is Mike Snarski. I'm the manager of Summit Laboratory out of Grand Rapids, Michigan.
Marissa: So the reason we wanted to get together and talk about water testing is because when it comes to doing FSMA compliant water testing it seems like growers speak one language, labs speak another language, and the FDA speaks a whole other language so it can be very tricky to figure out what you need from a lab, and how to find a lab that can give you the testing, the numbers, that you need to comply with the Food Safety Modernization Act. So we just wanted to have a conversation to help figure out how to get what you need from a lab.
So, in our experience reaching out to labs and figuring out if they can do the testing that's required by the law, we found that you can really get ping ponged around by the people who answer the phones, the sanitarian, all kinds of people can be involved in trying to figure out if the lab can do the testing you need to do. So we want to get a little input from Mike here, who's been on the other side of the line and can do the testing, on how to help you navigate this system.
So I want to run by a couple questions with you, Mike- things a grower might ask and how, what you as a lab, what you hear when a grower asks this question.
A grower might call up and start the conversation with, "can I get a water test from your company?" What do you hear when you hear this kind of question?
Mike: So when I receive a call from a farm that's doing the irrigation water testing, the main thing I need to know is what is the test for? Once they tell me it's irrigation water and they know that it's E. coli testing, then we know on our end what they need. They need the enumeration E. coli method on that water.
So, what it would transform into from there is I need to tell them there is a certain sample period time that they need to get that sample to us. There's paperwork that they need to fill out. We'd like them to fill out the paperwork ahead of time if they can. That paperwork should be available– if they don't have access to the website, we can email that to them. Otherwise, if they don't have that, we will fill that out when they bring the sample to the lab.
Marissa: Yeah, so you mentioned timing. One of the key parts about all the different testing methods under the rule is that it has a hold time of 6 hours, so that means you as a grower have 6 hours from the time you dunk that bottle into the water, take it from your spigot, whatever, to get it to the lab for testing. So you have a really short turnaround time. So it's important that, even before you call the labs, you know they're local and they're somewhere you can get in a pretty short turnaround time.
Do you have any tips, Mike, for when you're transporting the sample from the farm to the lab? How do you keep that sample good?
Mike: Key thing is that timing because you need to look at your scheduling, when you're going to collect that sample, do you have time to transport that sample to us pretty much promptly right after you collect it, how will that fit the schedule, making sure you're going to get to the lab within their normal business hour times. Our business hours are 8:30 to 5:00. Sometimes we can accommodate outside of those hours if you can't get to us in that time frame, but the main thing is, we have to receive that sample within that 6 hours. It has to be processed within that 6 hours.
What you want to do with that sample is, if you're holding it at any point in time you want to put that sample in a refrigerator or in a cooler with an ice pack. An ice pack is better than ice– we don't want ice melting and leaking and potentially contaminating the sample. What we would use is maybe a cooler box with an ice pack that you have designated for these types of samples. And keeping it on an ice pack, typically you're gonna be out in the field, so you probably have some type of carrying vessel for your containers, so a cooler box that's designed to hold temperatures, and then you can use that to transport that to the lab. The main thing is cooling it. After you collect it, keep it cool, don't let it get hot, don't let it get into direct sunlight. So if you're using some kind of carrying vessel it will protect it from that.
Marissa: Yeah, and when you're transporting it, it's also important that when you're taking the sample, before you even take it at all, that you have the right kind of sample bottle. In our experience, most labs in Michigan will provide you with a sample bottle. Mike, do you want to talk about what to look for in those?
Mike: Yeah. The thing is, what we are held to is they would state it as an approved container, and ideally an approved container is sterile. Those are best. We typically have those containers on hand. If you need several, we can provide you with that. That's the main thing is the sterile container, because you know when you put the sample in that that is what's being represented is just that sample– not what was in the container.
So our lab times, you know we're open from a Monday through Friday, we will accept samples Monday through Friday from 8:30am to 5:00pm, but we do on those days, if you're running towards the end of the day, ideally we want to see that sample by like 4:30pm so we have time to process that sample. If it's gonna run towards the very end of the day, let us know ahead of time. We're always willing to stay a little bit after to get that sample process but ideally we want that sample process by 5:00pm.
Marissa: Yeah. Another important question for a grower to ask is do you do the tests in-house? This comes back to that 6 hour hold time we discussed. If that lab is packaging up the sample and sending it out to the state lab in Lansing, you're gonna miss your 6 hour hold time and that sample's gonna be no good, so it's really important to understand that a lab is going to be able to do your tests in the 6 hour timeframe, which likely means being able to do it in-house.
Mike: Yeah, most definitely. The lab would have to do that, and what I would anticipate is that you're seeking out a lab that is certified by the state for the enumeration of E. coli. That is offered to labs. I know it's a Michigan DEQ requirement.
Marissa: One thing that I've run into when trying to figure out if labs can do compliant testing is the language "surface water". This is something that we talk about a lot with the rule. There's different testing requirements for water that the FDA call "surface water". What do you guys hear as a lab when you hear surface water, and how do you... what kind of information can the grower have to help you figure out what they're actually trying to get done?
Mike: Yeah. The main thing, like I said earlier, is if they know that this is ultimately for irrigation. Whether it's surface water, a well, you know, either way, it's still going to be tested for the same enumeration of the E. coli. We know that the surface water obviously is gonna have more of an influence from the E. coli than a well, but still they're going to be held to that same requirement to test for that.
Marissa: Under the rule, any water that touches the harvestable portion of the crop would be water that needs to be tested, so irrigation, even if it's, you know, water using for a fungicide spray that you need tested, irrigation might be a key word for a grower to use to help really break through with the lab at what you're trying to get done.
Another important thing I think to ask with surface water is if the lab can handle water that's cloudy or turbid. If you're taking the water sample from a stream or a pond, for example.
Mike: Yeah. The turbidity will have an influence. It does make it harder for interpretation of the results. Ideally, the less turbid, the better. If the water has some turbidity to it, it's just a natural turbidity, that's fine, but if it's something that's stirred up because you're getting into the water and you're stirring up the sediment and it's more turbid than normal, that will have an influence. We don't want to... we want to see that turbidity as less as possible. If it's a stream and you have to get in there, you know, obviously when you're going in, you're collecting up stream. The sample is collected upstream of you instead of down stream because you're going to be stirring that up. If you have to get into a pond or surface water, same thing, you know, getting in there and getting that sample collected as soon as you can so you're not stirring up a lot of sediment that's gonna be in there that naturally isn't there.
Marissa: So once you've figured out that the lab is able to test your surface water, it's really important to make sure you're using one of the EPA testing methods that has been approved by the FDA. So if you're calling a lab that's new, as a grower, it might be helpful to print out the list of approved methods. They're not easy to remember off the top of your head. They don't sound like regular English, so it can be helpful to have those printed off so that you can, if you're working with a new lab, kind of run through... "I'm looking for Quanti-Tray 2000... Colitert tests." Really know what you're asking for with the new labs so you can get what you want.
Marissa: As a lab personnel, is there anything you want growers to know as they bring you tests? Common mistakes you see in water testing?
Mike: The main thing is obviously the representation, making sure the sample just represents what you're collecting, making sure you're collecting it in what we would say is an aseptic way– you're not contaminating the inside of the container. The key thing is documenting the date and time that the sample is collected... identification of that sample, so when we report it that's what you want on the reports. The hold time that, you know, you're only allowed six hours, and the type of container, and how you're handling that sample from when you collect it to getting it to the lab. You don't want to go outside of that, and make sure that it's not a true representation of that sample.
Marissa: Yes, there are all kinds of things that could artificially cause your E. coli numbers to go up or down. It could be you didn't handle that bottle right, maybe you didn't think it was clean so you rinsed it out. You know, e. Coli is in the environment all around us. We have pets, we have kids... so we can introduce E. coli artificially into our water samples if we're not handling it correctly.
Mike: The other thing too is making sure you're collecting at least 100 milliliters of that sample. Most containers, they have an indicator around the container– if you're using an approved EPA container, it does have an EPA mark on there at the 100 milliliter mark. We want to make sure that you're collecting at least that. It can be more than that, bu tit needs to be at least 100 milliliters for representation.
Marissa: And if your lab is doing one of these approved methods and giving you a bottle, it should be the kind that's gonna give you the 100 milliliters you need to get one of these tests done.
Thanks, Mike! I think this is really helpful. Lots of good information there that can help growers around the state figure out how to get the water testing they need done.
So, let's talk a little bit about what the law wants to see in terms of your water testing.
Depending on your farm's gross annual produce sales, sometime between 2022 and 2024, farms will need to start building a microbial water quality profile. The numbers used by this profile are taken from a series of water tests. The water tests are meant to be representative of use, meaning you take them at the times while you're using the water, so you'd use it in time with frost protection, when you start your crop sprays, when you start irrigating, that kind of stuff.
The number of tests you need to take to build and maintain the profile vary by your water source. For municipal water sources, no additional testing is required. Instead, growers need to get documentation about the monitoring and treating of the water from their local municipality.
For ground water sources like wells, in the initial year of testing, growers need to take 4 samples to the lab. These 4 samples will be the basis of the microbial water quality profile. The next year, 1 new test has to be done, and then you'll kick out one of the original tests in your profile, add in the new one, and do your math over again. From here on out, you'll just be taking one water test to the lab a year, adding that one to your profile, taking one of your old numbers out of your profile, and redoing your math. You'll be eventually working off a rolling 4 test average for your microbial water quality profile.
Surface water sources like rivers, streams, canals, and holding ponds, are open to the environment. This means it is much harder to predict the quality of the water. Thus, these sources require more testing to build the initial profile. 20 samples have to be taken over the course of 2-4 years. Once you have these 20 samples, you generate your microbial water quality profile. The next year, you'll only need to take 5 tests to regenerate your profile. You'll kick 5 old tests out of the profile, add your new 5 tests in, and from there recalculate with your new 20 sample microbial water quality profile.
If you are currently testing, you don't need to do any radical changes yet. You're doing the right thing already. If you are a farm that has never tested your water before, it's good to start. As you can hear from this conversation, it can be really complex getting your water sampling regime in place and figuring out what labs can do the testing you need. So if you've never tested before, it's a good time to start talking to labs, taking some test samples, and figuring out how you're gonna work water testing into your farm's regular procedures.