Monitoring Water Pollution with Drones

Jonathan Brun


Una Jefferson: Would you start by telling a bit about who you are and what you do as a riverkeeper?

Brent Walls: Sure. My name is Brent Walls. I am the Upper Potomac river keeper for Potomac River keeper network. Our organization resides in DC. However, riverkeepers, are in our designated regions of the Potomac watershed. So I’m in the Upper Potomac. I work out of my home in Williamsport, Maryland. We also have a Potomac river keeper who works out of his home in Arlington and then Shenandoah river keeper, and he works out of Virginia. We are one organization of riverkeepers among 18 riverkeepers and the Chesapeake Bay. The closest count is about 300 riverkeeper organizations worldwide. This is definitely a movement not a local organization only kind of deal. So we are definitely a movement worldwide.

Una Jefferson: And what about the day to day work of being a river keeper look like?

Brent Walls: So riverkeepers are from all walks of life. They could be lawyers, photo journalists, scientists, you name it. Each one of these riverkeepers speaks for their river. They speak for their watershed, they keep an eye out for it. They look for pollution. In fact, one of the requirements for a riverkeeper is to patrol their watershed. We do this in the Potomac river through boats and canoes, we drive the watershed looking for pollution on the land, and we also fly drones and a fly planes to spot pollution issues from the air. All of these riverkeepers worldwide are required to patrol, inspect and then we use the state and federal environmental laws to hold polluter’s accountable. And that’s our main goal. We are there to make sure that the industries and even the state and federal government are abiding by the pollution control laws that guide them in what they can do.

Una Jefferson: So when I called you, you said you were in the middle of working with your drone, getting ready to do some monitoring. So what are you up to today?

Brent Walls: I am outfitting the drone with a new thermal camera. So I will be able to fly the drone, and with a thermal imaging camera on top of it, I can simultaneous see a real live image in a regular photo or video image and simultaneously see thermal video from the drone. We’re going to be using this to inspect thermal pollution issues in rivers and streams.

Una Jefferson: So you can see where warmer waters are being discharged where they shouldn’t be?

Brent Walls: That’s correct. There’s a situation up on the north branch Potomac where the discharge permit allows up to a hundred degrees Celsius thermal discharge into a cold water tributary of that has trout species in it. And so we’re going to use the drone to really understand and visually show people what kind of impact that thermal pollution has on the river system.

Una Jefferson: Okay. Well maybe let’s back up a bit. Let’s talk about your use of drones more broadly. How long have you been flying them for this job?

Brent Walls: I’ve been with the Organization for about nine years. I’ve been flying drones for about five years now. I’ve gone through a number of different drones over the years and I’ve settled on a small portable, DJ I Mavic pro, which is a pretty common, high grade high quality drone that’s out there. I’ve been flying this particular model for the past couple of years.

Una Jefferson: How has your use of drones changed since you started using them? What are some of the lessons that you’ve picked up along the way?

Brent Walls: Sure. So, well, avoid trees. Number one, avoid the trees. Even though they have pretty good sensors on them that are supposed to avoidance and obstacle detection and avoid those kinds of obstacles but it’s still a good idea to keep away from the trees. What I’ve learned is where to fly, when to fly. I had to take a a course, the FAA part 107 course and that is basically teaching me how to be a pilot. It’s teaching me how to read airspace on the map, how to read the weather systems that are out there so that I can fly safely. So I’m not going to interrupt or jeopardize other flying aircraft. Or any other circumstances that would promote the drone to be a projectile in heavy wind and weather systems. It was a really good course to be able to learn. And that’s important because in the beginning, I started out as a recreational flyer. And as a recreational flyer, you have certain rules. The main rule is you’re not supposed to fly above 400 feet. The secondary rules are that you can’t fly over crowds of people OR over traffic. You also have to stay within the line of sight. With the commercial license, you still have to stay within the line of sight but you can have visual operators along a long path. So I can actually fly the drone out about five miles away, but it’s sometimes really difficult to see that drone five miles away because it’s so small, right? So I’ll have spotters at certain locations to help me, understand if the drone is going to be in an area where there’s other flying aircraft and potentially be a hazard. I’ve learned to be able to really set up a mission, figure out a flight plan, check the maps to check the airspace, check the weather conditions to make sure that everything’s going to be safe and then follow certain rules that I have ethically and that’s not to drop below a 100 foot ceiling whenever I am over a property or industry or something that could become a liability.

Una Jefferson: Okay. The interest is respecting the privacy of individuals or trade secrets operations.

Brent Walls: Exactly. The other thing, I don’t want to fly over homes. I don’t want to have that personal property invasion. A lot of people will see a drone flying overhead and if it’s really low, they’re going to be really, really freaked out and I don’t want that at all whatsoever. So I will really try and minimize what my flight path will go over so I can have the least complications.

Una Jefferson: I’m also wondering about the footage that you gather from these flights. How often are you interested in using that footage as direct evidence in some kind of legal or regulatory process for using the footage to kind of tell you where to look on the ground.

Brent Walls: A lot of times when we’re looking at pollution issues, we can’t see it. A lot of times the discharge points or the discharge pipe is on another part of the property and it’s not close to a road or accessible by any other public means. Sometimes we’d have to go to an adjacent property owner to get permission from them to go see if we can see the pollution site to see if there’s a problem and even be able to collect a sample. So with the drone, I can pretty much circumnavigate all of that, go into a public setting right up the side of a road close to the site that I’m going and check the airspace. And then I can fly the drone up over the trees. And then with the visual imaging I can see what needs to be seen. I can see if there’s a problem. And if there is a problem, a lot of times what we do is go to the industry or the person themselves and say, ‘Hey, look, there’s a problem. We need you to fix it.’ A lot of times if that doesn’t work, then we would use that footage, going to the state and if the state doesn’t take any action, then we can use this footage in a clean water act case against a site.

Una Jefferson: You’ve been providing advice on this to some other people interested in monitoring in the area. What type of advice might you offer on best practices if you want to have your footage be admissible as evidence.

Brent Walls: The number one is get your FAA part 107 license or your commercial license. That is priority number one. Even though you’re working for a non-profit organization, you are collecting information on commercial entities in a commercial way that has legal ramifications. And so making sure that you are a licensed operator is going to be one of those checks that the lawyers will look at when the are reviewing a case. You don’t want to have your evidence thrown out of court because you don’t have a commercial license. Now we haven’t run into that. I don’t think anyone is running into that. And in fact, we have a clean water act case right now that we’ve collected evidence of an illegal discharged and we’re using that imagery evidence in this case. And so far it has not been challenged. So this could be one of the first legal environmental challenges that drone imagery has been used in as evidence.

Una Jefferson: Interesting. Could you share any more information about that case?

Brent Walls: It’s about a basalt mining operation in Pennsylvania that discharges in a tributary. And this small little headwater stream is inundated from an 800 Acre facility that discharges storm water into this very, very small tributary. The community reached out to me because they saw the branch being slowly degraded over a couple of decades and the mine wanted to expand and potentially discharge to a tributary to the north of the site. And that tributary, Toms creek has a designated high quality stream and they didn’t want that stream to start to look like a branch in the south. And so I got involved to kind of say, ‘hey, what’s, what’s going on here? How can we figure out, how can we help the community?’. The main thing was to do is to kind of track what was going on in the branch. And we took the drone up and we saw an illicit discharge coming from the pond, the storm water pond that was not on the permit. So we are using that imagery plus some water samples and other imagery on the ground taken by volunteers to show how this mining operation has been polluting the small tributary branch.

Una Jefferson: Can you give more detail about what types of pollution can you see from a drone. You mentioned thermal cameras. What types of things can you spot and how do you spot them and where is the technology not quite there yet.

Brent Walls: It’s a great camera system. It’s a 4k video, hi image resolution. It has some zoom capabilities, but you’re able to take it back to your computer and desktop and really zoom in and see the potential discoloration. A lot of times what we’re looking for is sediment discoloration. So you’re going to have turbid water. Sometimes you’ll be able to see foam and other visual evidence of something going on at a discharge point. We can also use the camera to detect algae. So you can see a blue green algae, you can see other different kinds of colored allergy. We can also use the drone and some really fancy software systems to where you can fly the drone and a pattern over a farm partial, let’s say. And this farm partial has a crop on it. The drone can pick up imagery and through a software process show what plants are thriving and what plants are not thriving. So areas of the farm that has good fertilization in areas of the farm that does not have good fertilization. And so that imagery can then be used to, recalibrate fertilization processes to better help the crops grow. We don’t necessarily do that as an organization, however, we can still use that same kind of technique to get depth profiles, which could be useful, and I have not tested it out yet, but could be useful in identifying sinkholes in certain areas before construction project starts. A lot of times sinkholes can lead to surface water to groundwater contamination. And there has to be mitigation circumstances that go with that and so we could use the drone to possibly find sinkholes.

Una Jefferson: If you were able to do that, would you find the information then hand over to industry and say, here, act on this?

Brent Walls : We would take that information and we would go to the state. We would probably use it in comments on a permit to say, ‘Hey, look, one, we don’t want this site here because it’s not a very good site because it may have numerous amounts of sinkholes’ or we can say, ‘hey, there’s only a couple of sinkholes here. We need you to make sure that you have some mitigation plans in place to make sure that there’s not going to be any surface water contamination of our groundwater.

Una Jefferson: You mentioned earlier that when you do find evidence of pollution happening, you often go the facility first before going to the state. What’s the reaction been like?

Brent Walls: So have maintained a pretty good connection with those sites that we go to with this information. And nine times out of 10, they will fix it, without us having to get the authorities involved or the state involved or even following legal action. Now when it comes to the drone imagery though, we haven’t really had an opportunity to say, ‘hey, look, here’s some problems. You need to fix it before we get the state involved.’ We’ve been saying to the state of Pennsylvania that this mining operation has been polluting the river. We have evidence, we have visual evidence at the stream, not even from the drone. And the state has failed to do a thorough inspection. And if they did do a thorough inspection, they would have found the illicit discharge. But they didn’t. And because of that reason, we didn’t go to the company and we went ahead and just skipped all of that and went to clean water act law suit.

Una Jefferson: It sounds like this technology could be used by industry, it could be used by state for monitoring and it could be used by you guys. Do you think civil society citizens, scientists are using this technology the most right now? How have regulators been reacting to this new potential?

Brent Walls: I think the regulators are stepping back and going, ‘Huh, okay, this is interesting’. Now the states are not using drones to do any kind of inspections, which I’m not sure if that’s something that they’re willing to do, but citizen scientist is where it’s flourishing big time and in fact it’s really flourishing in the advocacy side of things. So there is a movement in Virginia and West Virginia where folks that have drones are being trained to fly these drones to inspect erosion control sites along pipeline construction paths. And so we can develop a list of violations with this army of drones that are flying out there and then we can use that information to force the state to make some changes and if the state doesn’t do anything then we can and has been used to force the company to do stop work orders and force them to change things. So yeah, citizen scientist is definitely where it’s at. I think it’s being more and more used and in a really controlled situation. There are other riverkeepers in the area that are using the drones for inspection and for advocacy. So it’s definitely becoming a trend.

Una Jefferson: Do you anticipate that regulators might become interested in using this in the future? 10 years down the line when drone technology has kind of settled down a bit, what do you think the use of them for environmental monitoring will look like? Who will be using them and how?

Brent Walls :Typically in a permitted situation, the industry is the onerous to collect the samples, submit the sample results to the state. I would imagine that same industry, for instance, the gas industry could use their drones, do a thermal inspection of pipelines and then submit that data to the state for the state to review. As much as what I would love for the state to do the analysis and to do the research and the inspections themselves, our budget in the state’s budget’s just are not there yet. So hopefully, maybe in 10 years, the states might start to look into, using drones for visual inspections. It would be great, but until the budget increases or manpower increases, I don’t see it happening for quite some time.

Una Jefferson:  I thought I’d read that the Michigan Environmental Department was experimenting with Drones Monitoring.

Brent Walls: I haven’t heard that, but that’d be great if they are. Interestingly, I just got off the phone today with a gentleman down in the bay area on the Potomac, where he is connected to a water testing lab that works with Virginia DEQ. And what we’re considering is doing some tests trials of using drones to collect water samples, the physical water. And then carry that physical water back to a stationary place where then it could be run and taken to the lab. Instead of wasting a lot of gas and motorboats to go to all these different sites, they can cut a whole lot of time and expense by flying a drone, lowering it down, lifting it up and collecting a water sample and then taking it back to a stationary site and or outfit the drone with meters systems that would collect temperature, Ph, turbidity, nitrate nitrogen, a number of other different parameters. I’m really thrilled to kind of work with this group to kind of embark on this kind of new technology and new way of using drones.

Una Jefferson: It sounds like a real labor saver. Are you worried about being automated out of your job as a riverkeeper?

Brent Walls : No there’s still someone always going to have to be there to fly the drone and then have to analyze the result. So I’m not too worried about it, but it is definitely absolutely fascinating.