superfund sediment site

Diving Green for Science

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.

Editor's Note: The opinions expressed here are those of the author. They do not reflect EPA policy, endorsement, or action.

Please share this post. However, please don't change the title or the content. If you do make changes, don't attribute the edited title or content to EPA or the author.

Drilling for Water – Underwater

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. 

Editor's Note: The opinions expressed here are those of the author. They do not reflect EPA policy, endorsement, or action.

Please share this post. However, please don't change the title or the content. If you do make changes, don't attribute the edited title or content to EPA or the author.