diving scientist

Jul 17, 2013

Diving into Nutrients: How much is too much?

diving scientist, epa dive, Nutrient pollution, Nutrients Management, Scientific diving 4 Comments

By Sean Sheldrake

An EPA diver kept isolated from contaminants.

There’s a nutrient “problem”?

Did you know nutrient pollution, primarily in the form of too much nitrogen and phosphorus, is one of the nation’s most widespread, costly and challenging environmental problems? Some 16,000 waterways are impaired, and 78 percent of assessed coastal waters suffer from nutrient pollution, affecting water used for drinking, fishing, swimming and other recreational purposes. These impacts also threaten tourism, home and property values and public health.

Nitrogen and phosphorous are food for some plants, like algae, and too much can spark a large algal bloom that can end up consuming all the dissolved oxygen in a waterway, causing fish to be starved for that critical gasp of O². Fish die-offs are common with extreme nutrient problems.

Where does it come from?

Excessive nitrogen and phosphorus are often the result of human activities. Primary sources include agriculture (manure, excess fertilizer and soil erosion), inadequately treated wastewater, stormwater runoff, air pollution from burning fossil fuels and—us! Huh? Whenever we do things around the house that add nitrogen and phosphorus to the local watershed we are part of the problem. That can include not cleaning up after your dog, using too much fertilizer on the lawn or garden, or washing your car on the driveway (most soaps contain nutrients).

How can I help?

Washington Department of Ecology Image.

The good news is that since we are all part of the problem, we can all be part of the solution.

Bag the dog waste, apply fertilizer according to the label (or better yet, switch to using some backyard compost!) and park your car on the lawn instead of the driveway when you wash it, or go to a carwash. We can really make a dent in the problem.

How about a little science to help out?

But it’s not all up to individuals alone. EPA scientists are working on solutions, too.

EPA divers help deploy and retrieve scientific instruments, such as Acoustic Doppler Current Profilers (ADCPs), to help study nutrient pollution. For example, in one project in Puget Sound we deployed ADCPs to collect information on water flow, a critical first step that EPA computer modelers use to calculate the level of nutrients a water body can tolerate. Ensuring the proper placement for data collection is paramount for data quality.

EPA diver deploys an ADCP.

Getting into the water can be a challenge though! Divers may have to upgrade to protective equipment and do a decontamination wash after the dive to ensure the safety of each diver getting in the water to collect data.

Read more about the latest in EPA scientific diving at facebook.com/EPADivers.

About the Author: Sean Sheldrake is part of the Seattle EPA Dive unit and is also a project manager working on the Portland Harbor cleanup in Oregon. He serves on the EPA diving safety board, responsible for setting EPA diving policy requirements.

Join us for a Twitter Chat to Learn More!
Got questions? Want to learn more? Join us for a Twitter chat this Thursday (July 18, 2013) at 2 pm ET on nutrient pollution and harmful algal blooms. Use #waterchat to ask a question or participate. Not on Twitter but have a question? Please add it to the comments section below.

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Jun 17, 2013

Diving Safety: We’re All In

diving scientist, epa dive, Scientific diving, scientific diving exemption 0 Comments

By Sean Sheldrake and Alan Humphrey

Our previous blog posts have featured how EPA diving scientists support cleanups in the nation’s waterways. In this post, we talk about how our divers stay safe through the development of safe practices and standards, well before they hit the water, so that the best science is delivered safely.

Sometimes things go wrong

We’ve all heard about a diver fatality at one time or another in the news, and such tragedies are particularly hard hitting when it is a colleague. The dive community is a close knit one, and these tragedies hit close to home. A diver’s death brings us together to grieve and—perhaps more importantly—to learn. Are human factors the source of what occurred or should our safety rules be changed so we don’t have a similar event? We work to prevent repeating mistakes, and avoiding future tragedies. “Near misses” are evaluated for safety protocol improvements as well.

Peer groups make the difference

The diving control board meets to discuss safety.

Under the Occupational Safety and Health Standards for scientific diving, scientific divers must operate under a “diving control board” that meets regularly to update their standards for recent safety issues. Annually, the control board meets to discuss safety incidents that occur with military, commercial, or scientific divers and determines how to change the diving rules to keep us safe.

Beyond our own control board, we look to other “standard setters” in the dive industry. The American Academy of Underwater Sciences, Association for Dive Contractors International, and others develop standards that exceed basic OSHA requirements. Indeed, this type of diving safety peer review is part of the reason why the data suggest scientific diving is among the safest forms of diving (Dardeu et. al., Diving and Hyberbaric Medicine, 2012). Developing “best practices,” such as sharing critical information across the profession is key for working safely in such an unforgiving environment!

Always learning

Divers learn early that their training never ends. In addition to learning from diving accidents and standards of industry, the board disseminates critical new information to divers on the ground.

Deputy unit diving officer Chad Schulze demonstrates a new first aid oxygen delivery system.

Though the demands of the underwater environment are relatively static, technology changes much of what we know about the effects of pressure on a diver’s body. Sifting through new research, changing dive rules, and informing working divers about new practices is the control board’s number one job in keeping EPA divers safe.

EPA’s diving culture is all about safety. Every diver can refuse to dive for any reason, and every divemaster can call off a dive. Not only have each of us aborted more than one dive, we often gauge newer divers most on their concern for safety. Have they considered not diving due to a cold, an equipment issue, or just a feeling that the stars are not completely aligned? That’s what we want. Whether it’s conditions, equipment, or anything else, we all work together to pursue our underwater science safely.

Read more about the latest in EPA scientific diving at facebook.com/EPADivers.

About the authors: Sean Sheldrake is part of the Seattle EPA Dive unit and is also a project manager working on the Portland Harbor cleanup in Oregon. He and Alan Humphrey both serve on the EPA diving safety board, responsible for setting EPA diving policy requirements. In addition, they both work to share contaminated water diving expertise with first responders and others.

May 21, 2013

Ebb and Flow: Feeling Like a Yo-yo

Diving, diving scientist, epa dive, groundwater discharge, Scientific diving, seepage meter 0 Comments

By Sean Sheldrake

My previous blog posts have featured how EPA diving scientists support cleanups in the nation’s waterways. In this post, I talk about how our divers study the connection between groundwater and our waterways to support EPA cleanups. (Hint: it’s not a one way street!) Understanding which way groundwater is flowing is critical to implementing a successful cleanup—and protecting our nation’s waterways and oceans.

Groundwater: coming or going?

We all know storm drains connect to our waterways, but how about groundwater? In a given stretch of a stream, lake, river, or the seafloor, groundwater may be feeding the waterway—or the opposite—that stream, lake, river, or ocean could be losing water into groundwater in that location. The direction of the flow can change by the hour, day, season, and conditions (such as drought)—a reality of the interconnectedness of water in the environment.

Gaining or losing? Mapping out the flow to get the cleanup right

Determining whether a river loses or gains water from the ground is a big deal when devising the best course of action to take during cleanup activities, as we need to follow the contaminated water to wherever it goes. With this information, we can decide on important details, such as where to install caps in a riverbed to stop the flow of contaminated discharge, or how many and how fast pumping wells should be employed to move contaminated groundwater to a treatment plant.

Seepage meter installed by an EPA scientific diver near a Superfund Site in Lake Washington. Photo: Rob Pedersen, USEPA.

Making such a determination is an ongoing process. For example, in an estuarine river (the part of a river that is near the sea), this may take a lot of monitoring locations over time to know we’re choosing the right kind of cleanup. A lot of factors also need to be considered, including the location, direction, and volume of local ship traffic. EPA divers often must check various locations in the sediment near an active cleanup to determine where groundwater is discharging into the river—and vice versa.

Low-tech goes underwater

At some sites near marine environments, we use conductivity mapping to determine where groundwater discharge is occurring. Because salt water conducts electricity better than fresh water, we tow an array of electrical cables that measure electrical fields to produce a map of where fresh ground water is discharging into salt water. In other sites, we can use a more low-tech approach.

The photo above shows one such technique. Here, we use a five-gallon bucket, cut in half, stuck into the lake bottom. We then outfitted it with a sampling bag filled half way with water. We use this simple device to determine the direction of the water flow by noting what happens to the sampling bag. If it begins to empty we know the direction of water is OUT of the lake (and bag) and into the ground, and if it fills up, we know the water is flowing in the other direction: from the ground into the river. We can also seal the bag and bring it to our lab for analysis, getting and even better understanding of the rate of contaminant discharge into a lake or stream. Over time, divers come back to visit the site to map the wonderful complexity of water’s connections. The map allows us to understand the movement of historical pollution and to determine how to best conduct a clean up.

Read more about the latest in EPA scientific diving at facebook.com/EPADivers.

About the author: Sean Sheldrake is part of the Seattle EPA Dive unit and is also a project manager working on the Portland Harbor cleanup in Oregon. Sean Sheldrake serves on the EPA diving safety board, responsible for setting EPA diving policy requirements.

Apr 12, 2013

Diving for Science at EPA: ‘SCUBA’ or ‘Surface Supply’?

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By Sean Sheldrake and Alan Humphrey

Our previous blog posts have featured how EPA diving scientists support cleanups in the nation’s waterways. In this post, we talk about different ways in which we might dive to carry out EPA’s mission.

What is SCUBA?

Self-contained Underwater Breathing Apparatus, or “SCUBA,” is the mode of choice for many diving scientists, and many diving scientists at EPA. It involves carrying your entire breathing supply with you, and requires a fair amount of strategic planning, especially for difficult diving conditions such as low visibility, and cold or polluted water.

What is surface supplied diving?

An EPA surface supplied diver entering the water. You can see the hose providing air to the face mask, and the emergency breathing gas (yellow bottle) on the diver’s back. Photo by Rob Rau, USEPA.

Is that a trick question? Well no, it is what it sounds like—air is provided to the diver from above through a long hose. This can be quite limiting if you want to swim far from the boat, so it doesn’t work everywhere. Also, the dive vessel must be anchored to keep it from moving. If the vessel was moving, the diver working on the seafloor could become the boat’s anchor after drifting into a rock. Now that’s a bad day at the “office”!

Even though this kind of “dope on a rope” diving may feel restricting to the diver, it can be crucial in low visibility, contaminated water. Often times—especially where visibility is only a few inches—it can be difficult or impossible to keep track of your dive buddy.

I’ve been diving in the Willamette River in conditions where I’ve been close enough to hear my dive buddy’s breath, but we couldn’t see each other. In conditions like that, we might not be able to find each other in case of trouble. And even more basic than that, divers can’t check vital gauges such as pressure and air supply under such conditions. In those cases, surface supply is the way to go. Topside support can be your ‘buddy’!

Don’t hold your breath!

Photo of an oil covered diver undergoing decontamination on surface supply. Photo by Alan Humphrey, USEPA.

With a surface supplied diving system there is plenty of air to keep the diver working. That means no cutting dives short before the scientific mission on the bottom is completed, or needing to account for an air supply that includes keeping the diver completely sealed in for an extended decontamination process, like when they might be covered with oil (see picture). Surface supply offers more efficiency and safety for the diver for certain projects—in most cases the diver can continue to work until the sampling or other task is completed (or when nature calls).

Want to learn more? Download the EPA publication “Use of Surface-Supplied Gas for Scientific Diving” presented at the 30^th symposium of the American Academy of Underwater Sciences: http://1.usa.gov/ZPxS6b.

Read more about the latest in EPA scientific diving at facebook.com/EPADivers.

About the authors: Sean Sheldrake and Alan Humphrey both serve on the EPA diving safety board, responsible for setting EPA diving policy requirements. In addition, they both work to share contaminated water diving expertise with first responders and others.

Mar 15, 2013

Diving into the Classroom

diving scientist, earth day, epa dive, science in the classroom, Scientific diving 0 Comments

By Sean Sheldrake

Bona fide “cool” job: an EPA diver maps the location of a drum found on a dive survey.

My previous blog posts have featured how EPA diving scientists support cleanups in the nation’s waterways. In this post, I cover one of my favorite work experiences I do “top side,” namely, talking about my scientific diving experiences in the classroom.

I have found that being a professional diver is a bona fide “cool” job. Not only does this make sharing my work with students fun, but is a great opportunity to energize kids about math and science and illustrate how we can all take action to help protect the environment.

Raise your hand…

I like to start out by taking questions from the students. Often, one of the first is: “what’s the ‘scariest’ thing you’ve encountered underwater. “Sharks?” No, but I was pretty scared during my first Alaska dive surrounded by hundreds of sharks—so many they were getting stuck in the crooks of my arms while I attempted to take photos. “Eels?” No, in fact I actually find wolf eels pretty cute, though one did come out of its den and chase me on one memorable dive!

I almost always get surprised, quizzical looks when I reveal the real answer: “a pipe discharging really mysterious stuff.” I explain how real harm can be done to the diver and the ecosystem if harmful chemicals, bacteria, viruses, and alike are discharged into our lakes, streams, and oceans.

The other “scariest” thing I’ve seen: stormwater runoff!

Contaminants—used motor oil, metals, pet waste, too much lawn fertilizer, cigarette butts, etc.—that get swept up by stormwater can be very harmful to water bodies, unless we each work hard to keep those things where they belong. Fixing car leaks, recycling and composting, cleaning up after our pets, following the instructions on lawn fertilizers, and other daily actions are all things we can do to make a big difference in what washes off the street and goes down the storm drain, where it can eventually cause major damage downstream. It all adds up.

“Does math really have any use?”

And speaking of “adding up,” the other major point I like to make in the classroom is dispelling the myth that math and science are some kind of torture. They are critical subjects to some of the coolest jobs out there (such as scientific diving)! After all, multiplication gets exciting when I say that if I don’t know my multiplication tables me and my dive buddy could miscalculate our dive plan and get hurt. Safe diving science requires math! (EPA has lesson plans for oodles of environment topics that help bring science and math to life.)

Parting thoughts

I always try to leave the students with the knowledge that there are a million things each of us can do to help the environment! Well, okay, maybe hundreds of ideas growing by the day. The most important aspect is to take personal action.

If we all take steps to help our planet it will really add up; for my part maybe that storm drain (yikes!) won’t cause the hairs to stand up on the back of my neck anymore.

Read more about the latest in EPA scientific diving at facebook.com/EPADivers.

About the Author: Sean Sheldrake is part of the Seattle EPA Dive unit and is also a project manager working on the Portland Harbor cleanup in Oregon. Sean Sheldrake serves on the EPA diving safety board, responsible for setting EPA diving policy requirements.

Jan 14, 2013

Diving Green for Science

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By Sean Sheldrake

EPA’s Seattle dive van loaded up with a full ton of dive gear—plus a bicycle.

In previous blog posts, we’ve shared how EPA diving scientists support cleanups in the nation’s waterways. In this post, I’ll talk about how we are working to “dive green” while undertaking EPA’s mission.

Getting On Site

Getting on site to conduct a scientific survey usually involves using some kind of vehicle. So, we do it as “greenly” as possible:

Our gear and our divers like to travel together! The dive van gets virtually the same mileage whether it carries one diver or four – travelling together saves tax dollars.
Van pooling this way lowers our environmental footprint – fewer emissions of air pollutants protect the air we breathe and there’s less pollution to wash into our waterways and ocean ecosystem when it rains.
Did you know most brake pads contain metals that hurt fish? Fewer vehicles on the road also lowers the amount of pollution from brake pads getting into the environment and washing into the ocean ecosystem.
And we try to be creative – one of our divers bicycled to and from the boat launch to a friend’s house! You can see the bike tucked into the van in the photo above.

No American Idle

EPA vessel at anchor with divers below.

Whether it’s our van or our vessel, we cut the engine whenever possible. After all, what’s good for kids riding on school buses is good for diving scientists carrying out EPA’s mission. Many of our van drivers are surprised to learn that it’s more efficient to turn the engine off than let it idle for even 30 seconds!

Reducing engine use is important for our vessel, too, since it’s mainly powered by diesel engines, which can generate large amounts of particulates as well as sulfur and nitrous oxides. Anchoring and turning off the engine helps keep the air and our waterways cleaner.

Diving Scientists Need to Eat

EPA diver with a wireless communication unit.

Once out on the vessel divers are a hungry bunch! We pack meals and plenty of snacks, and carefully separate out all compostable material and recyclables to bring back to the lab for proper disposal. On one recent trip on the Elwha, our crew kept some 60 pounds of trash out of the landfill!

“Scotty, I Need More Power!”

Our underwater lights, communications systems, and scientific equipment run on a lot of ‘juice,’ so to cut waste we use rechargeables. Just one diver using a wireless communications unit to talk to their buddy diving and to their “tenders” topside can go through up to forty AA type batteries per week! Rechargeable batteries that conk out after a few hundred charges get added to the recyclables we take back to the lab rather than sent to a landfill where they might leach heavy metals.

EPA divers make a positive impact on the ocean environment in the work that we do, and the green way we do it. It’s also a positive example that we hope inspires divers and diving scientists elsewhere! What else can you think of to reduce our footprint?

Read more about the latest in EPA scientific diving at facebook.com/EPADivers.

About the author: Sean Sheldrake is part of the Seattle EPA Dive unit and is also a project manager working on the Portland Harbor cleanup in Oregon. He serves on the EPA diving safety board, responsible for setting EPA diving policy requirements.

Dec 11, 2012

Looking for Sea Monsters

diving scientist, epa dive, Invasive Species, Scientific diving, sea squirt 3 Comments

By Phil Colarusso

Tunicates covering native eel grass. Photo by Dann Blackwood.

As a diver for EPA, I am often asked, “what’s the scariest thing you’ve ever seen underwater?” Most people expect the response to be sharks or stingrays. They are generally disappointed and perplexed when I say sea squirts.

Let me explain. Sea squirts, also known as “tunicates,” are seemingly benign-looking gelatinous, filter-feeding animals. They grow in large colonies or as individuals. They don’t bite, sting or even generally move, once they have attached themselves to a solid object, like a rock or pier.

So why the concern? Well, here in the northeast, like many other places in the U.S., we’ve been experiencing an invasion of non-native tunicates. Mooring lines, piers, boat bottoms, rocks, shellfish, and even eelgrass have been overgrown by various invasive sea squirts. Anything that does not move quickly is at risk of being engulfed by the rapidly reproducing and growing colonial species of sea squirts.

Sea squirts are prolific filter feeders, processing more water per unit body weight than oysters, blue mussels or quahogs. Very few animals feed directly on them because they are not a native species.

Our dive unit has been studying the impact of these invasive species on the ecology of coastal salt ponds on Martha’s Vineyard. We initially became interested in this topic while doing eelgrass restoration work, when we noticed large numbers of eelgrass shoots covered with exotic sea squirts.

Tunicates cover a boat hull. Photo by Dann Blackwood.

As part of our study, we quantified the abundance of invasive sea squirts in a number of coastal ponds on Martha’s Vineyard. We quantified the short term impact of the presence of sea squirts to eelgrass by measuring plant growth, size and morphology and sugar concentrations (end product of photosynthesis). Finally, we measured light reduction by sea squirts.

We found that sea squirts reduce the amount of ambient light that reaches the plants by between 70-80 percent. Plants covered with sea squirts grew at a much slower rate and had fewer leaves per plant, so the presence of sea squirts was having a measurable negative effect on eelgrass.

We recently began a new study designed to look at the impact that sea squirt feeding may have on the normal food web dynamics in these coastal salt ponds. We will be using stable isotopes to construct food webs in a test pond with an abundance of sea squirts and compare that to a comparable pond without sea squirts.

The sea squirts are likely competing with native commercial shellfish species (scallops, mussels, quahogs, oysters) for food. Our concern is that an explosion in the abundance of the exotic sea squirts could result in upsetting normal food web dynamics, potentially reducing populations of commercially important shellfish.

The scariest things in the ocean don’t always look that way!

About the author: Phil Colarusso is a marine biologist in the EPA Region 1 Coastal and Ocean Protection Unit and a member of the EPA New England Dive Unit. He’s been with EPA since 1989.

Read more about the latest in EPA scientific diving at facebook.com/EPADivers.

Nov 27, 2012

Drilling for Water – Underwater

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By Sean Sheldrake, Rob Pedersen, and Alan Humphrey

In our previous blog posts we’ve talked about how EPA diving scientists support cleanups in the nation’s waterways through collection of samples. In this post, we’ll talk about miniature wells called “piezometers” that we and other divers place underwater.

What is a piezometer and what is it doing at the bottom of the river?

Photo 1: close up of a piezometer.

A piezometer (see photo 1) is a miniature well that lets us sample shallow groundwater—essentially a metal tube with a filter on the bottom to allow water to flow in, but keeping most sediment out. They can be installed both on land and underwater.

But why on earth would someone underwater want to drill for more water?! We do it to study pollution.

Groundwater that is contaminated by an upland industrial site can discharge into rivers and sounds. By the time that contaminated groundwater mixes with the water column, the pollution is difficult to detect. Worse yet, concentrations are far higher in the seafloor or river bottom, potentially harming critical links at the beginning of the food chain. If levels of groundwater contamination aren’t measured accurately and in the correct place, a big piece of the pollution puzzle could be missed.

How do you collect a well sample at the bottom of an estuary? Here’s what it looks like when we work:

Tending the diver and groundwater sample tubing is a tough job!

Photo 2: preparing piezometer and tubing from the surface.

A surface supplied diver (see photo 2) takes the metal piezometer from the boat to the bottom while spooling out tubes that connects it to the boat or dive platform.

Don’t get tangled! Once underwater (see photo 3), the diver must be very careful to keep all their lines from being tangled; the slightest misstep and the sample line running to the surface could be pulled out, requiring the process to be restarted.

Photo 3: EPA divers work carefully so they don't get tangled.

(Also see our previous post: Underwater with EPA Divers.)

With the tubing placed, water is pumped through the tube to the surface and checked (see photo 4) on board against samples taken from upland wells to ensure the right kind of sample is being taken. We pump water for the sample for 30 minutes to an hour, depending on the rate at which water will flow through the sediments. Then it’s time to move to the next spot.

Photo 4: EPA staff collecting a sample.

With the data we collect, cleanup managers can determine whether groundwater and sediments require a cleanup, and once it’s started, whether it’s protecting the water.

For more information on EPA’s groundwater collection techniques, underwater, see: Adaptation of Groundwater Evaluation and Sampling Tools for Underwater Deployment.

Read more about the latest in EPA scientific diving at facebook.com/EPADivers.

About the authors: Sean Sheldrake is part of the Seattle EPA Dive unit and is also a project manager working on the Portland Harbor cleanup in Oregon. Sean Sheldrake and Alan Humphrey both serve on the EPA diving safety board, responsible for setting EPA diving policy requirements. In addition, they both work to share contaminated water diving expertise with first responders and others. Rob Pedersen is an EPA diver with decades of experience in environmental sample collection, and has also served on the EPA safety board.

Oct 24, 2012

Going Digital: Underwater Science Photography at EPA

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By Sean Sheldrake, Rob Pedersen, and Alan Humphrey

EPA scientific diver Sean Sheldrake takes pictures with a Nikonos V film camera. Photo by Joe Goulet.

If you’ve followed EPA’s photo series “Documerica,” you may have noticed a drastic improvement in the quality of the images. That evolution has been equally as dramatic for underwater photography as it has been above ground—and it’s been personal for us and our fellow scientific divers.

Mama Don’t Take my Kodachrome Away.

For years, we used specialty, underwater, film-based cameras. Although they were state-of-the-art for underwater work, our cameras were rather simplistic compared to their above ground counterparts, especially with the earlier cameras which lacked even built-in light meters. It was a love/hate relationship.

At times, one of us would forget to rewind the film, ruining the pictures from the dive. Of course there missed shots, too: “That shark came by right after I finished my roll!” More times that any of us can count we’d reach the end of the roll before finding an item in our survey area that needed to be photographed.

In the end though, dialing in the focal range, previewing the depth of field, and setting the aperture settings was so classic, so pure, that we grew very attached to our equipment.

Then, the digital photography revolution hit, and we couldn’t even get our film of choice developed locally anymore.

It turned out to be just the kick we needed. Digital has been a whole new world. It’s a lot easier when you can shoot 1,000 pictures on a memory card instead of 36 on a roll of film. For subjects that don’t move, you can literally shoot and check your photo quality underwater—as long as your air supply (and dive buddy) will allow.

Rob Pedersen shooting video with an older video camera in a large silver housing.

Video was a similar evolution. Taking early video cameras underwater involved using heavy, bulky housing to keep the ravages of salt and fresh water damage out. Whatever we shot required “dubbing” the original tape to another format for sharing with research partners, often taking days of work. Today, sharing is as easy as downloading to a DVD or a thumb drive. And what’s more, it’s common place these days for still cameras to shoot video, and visa-versa—no more need for two cameras.

Read more about the latest in EPA scientific diving at facebook.com/EPADivers.

See our photos on Flickr.

About the authors: Sean Sheldrake is part of the Seattle EPA Dive unit and is also a project manager working on the Portland Harbor cleanup in Oregon. Sean Sheldrake and Alan Humphrey both serve on the EPA diving safety board, responsible for setting EPA diving policy requirements. In addition, they both work to share contaminated water diving expertise with first responders and others. Rob Pedersen is an EPA diver with decades of experience in underwater photography, and has also served on the EPA safety board.