Workplace Garden Challenge: Plants, soil capture dissolved zinc and copper in TOTE’s rain gardens

Seen those lovely gardens around the shops at TOTE?

They’re working harder than stevedores.

They are rain gardens, rigged with plumbing systems and filled with filtration layers and native plants. Each year, they grab dissolved zinc and copper out of a quarter million gallons of storm water.

Rand Lymangrover, the terminal’s operations manager, had barely heard of rain gardens in 2010, when they were generating buzz with environmentalists. But when TOTE faced new clean water benchmarks, he hit the learning curve hard.

“We have a general storm water permit from the state,” Lymangrover said. “That requires that you do certain things to meet standards with outfall into the Blair Waterway. In 2010, they came out with more stringent requirements, and we were not meeting the benchmarks.”

TOTE was not out of compliance with regulations, he said. The water they were sending into the waterway was crystal clear. But they were not meeting the higher standards attached to their permit. Tests showed minute traces of zinc and copper.

Lymangrover looked for the sources, and found them in TOTE’s infrastructure. Buildings erected in 1984 have galvanized metal in their roof structures and downspouts. The fencing surrounding the shipping terminal is made of galvanized metal.

It’s zinc that coats galvanized metal and retards rust, and zinc leaches off in the rain.

TOTE already had a good runoff purification system. With the new benchmarks, it faced spending $1 million or so to build a better one.

Carrie Hernandez of Citizens for a Healthy Bay came to look over the site and the problem.

“Why don’t you try rain gardens?” she asked Lymangrover.

“At first I thought, geez, I don’t know about that,” Lymangrover said. “Then I thought of a couple of places where we could try it.”

One of them faces 11th Street East and Alexander Avenue, along the side of the dry-out shed.

Totem Ocean Trailer Express, TOTE to its friends on the Tacoma-to-Anchorage-and-back-again container ship route, has a big green streak. It sends its recyclables to companies on the Tideflats. It installed efficient lighting and cut its electricity consumption by 23 percent. It installed shore power, so its ships can plug into the dock rather than keep their diesel engines running while they’re moored. They have removed excess fencing and cover other stuff, like tires, that might leach pollutants.

So it made sense to Lymangrover to give the rain gardens a try. David Hymel of Rain Dog Designs took on the job with AHBL, Inc. and designed the system.

On April 19, 2011, 75 volunteers showed up to fill the gardens with soil and 600 native plants, including strawberry ground cover donated by Tacoma Garden Club. Those volunteers represented Washington State University stewardship extension service, AHBL, Inc., Citizens for a Healthy Bay, Stewardship Partners and Rain Dog Designs.

As best they can figure, they built the first industrial rain gardens on Puget Sound.

Out front, facing Alexander Avenue, galvanized downspouts capture all the rain from the dry out shed roof and send it into the system that carries it into the rain garden. From the street, it looks like landscaping instead of a hard-working water purifier.

On the side, by the machine shops, the gardens are more complicated.

They capture roof water, and handle the storm drains.

“We have two big pumps in the storm drains,” Lymangrover said. “Before the water gets to the outfall, they pump it back through two plastic tubes to the rain gardens. They seem to accept it.”

TOTE is trying out an addition, a deep tub called a splash box. Pipes in the box diffuse the water to ease its pressure on the lower garden.

Lymangrover figures the gardens cost about $8,000 each, and that spending $24,000 for a simple, durable solution is smarter than putting $300,000 to a million or so into a complex system.

That’s what he tells everyone who asks to see the gardens. People call so much, he said, that TOTE has become a demonstration garden, and an inspiration.

“They’re going in all over the place,” Lymangrover said. “They’re a relatively inexpensive way to deal with storm water. The way to start is with the simplest solution.”

A solution as simple as soil, strawberries and a little extra plumbing.

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