October 2007 ISSUE

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KEYSER FILE

Contaminated No More

BY TOM KEYSER
Freelance Columnist

A clean and functional tranquillity replaces a light industry site in southeast Edmonton, as an APEGGA permit holder demonstrates that environmentalism goes hand in hand with good engineering

ENGINEERING FOR NATURE -photo by George Lee Mill Creek Roper Pond has all the tranquility you’d expect from nature. The surprise is that it only exists because of award-winning engineering. The man-made pond is a key accomplishment in a reclamation and stormwater retention project, in southeast Edmonton.

Semis and flatbed trucks rumble back and forth on a busy thoroughfare about a block away. But they can barely be heard at the tranquil urban oasis you’ll find north of the warehouses and factories lining Roper Road.

For decades, the southeast Edmonton site was home to light industry. A sandblasting company, a logging concern, an auto mechanic and a storage firm — all did business here.

Sadly, their legacy was tonnes of trash and a contaminated landscape.

Then along came Herb Kuehne, P.Eng., and a group of environmental experts from Associated Engineering. They made the mess a memory and in the process created the Mill Creek Roper Pond, a hospitable habitat for countless waterfowl, cattails and other living things, flora and fauna.

It’s also a great place for us humans to take a stroll.

True Green
Both the pond and the surrounding marshy wetlands stand as a living testament to the mini-miracles modern engineering teams can accomplish when enlightened clients, like the City of Edmonton, give them the green light.

“I’ve always believed that engineers are the true environmentalists,” says Mr. Kuehne, an Associated Engineering vice-president who quarterbacked the reclamation of an abandoned, badly compromised piece of city property.

The company also created an attractive and functional stormwater retention pond. It eases flood pressure on a key storm trunk sewer, known as Argyll Tunnel, which directs flow from Mill Creek into the North Saskatchewan.

Associated Engineering set out to add water storage capacity upstream of the trunk while finding natural ways to reduce the amount of sediment carried away by stormwater runoff. It was all part of the APEGGA permit holder’s long-term commitment to help the City of Edmonton implement its sustainable watershed management plan.

The resulting slice of paradise thoroughly impressed judges for the 2007 Showcase Awards, presented by the Consulting Engineers of Alberta. For the project, Associated Engineering pulled down an award of excellence in sustainable design and an award of merit in community development.

The Dirty Part
Looking back, Mr. Kuehne describes the project as one of the most satisfying experiences of his career. But when he’s casting about for pleasant memories, the massive clean-up part is low on the list.

“It was a fun project but extremely challenging,” Mr. Kuehne recalls. “We never seemed to stop finding buried tires or rubble buried along the banks of the creek. The amount of debris far exceeded our expectations.”

Over the decades, stands of poplar had flourished atop ancient piles of discarded tires and layers of silt-covered concrete slabs from abandoned buildings. More alarming was the extent of chemical contamination.

Mr. Kuehne and his colleagues, Alan Miller, P.Eng., and Jeff Fetter, P.Eng., found beneath their feet everything from lead to zinc to petrochemical spillage. In the end, they hauled 6,500 tonnes of general waste, concrete and steel from the site, while digging out more than 5,500 tonnes of contaminated soil.

With the cleanup finally behind them, the Associated team set about creating a new and natural landscape, while Mill Creek continued to meander past.

“Our primary goal was to maximize the pond’s capacity for water storage,” Mr. Kuehne explains. “We tried to sculpt the pond in the manner of a typical wetland. It’s not a matter of straight lines — you’re trying to make everything as natural as possible, to maintain the original ecosystem while adding new natural elements.”

Meanwhile, subconsultants EIDOS Consultants and Spencer Environmental recommended 18 plant species. These were carefully chosen to provide an ideal habitat for water birds — while using the wetlands to naturally filter waste nutrients such as phosphorous and nitrogen, and thereby improve Mill Creek’s water quality.

Said And Done
How did it all come out? If you haven’t been there in a while, take a casual ramble past the quiet waters, the cattails and the feeding mallards.

That should confirm Mr. Kuehne’s evaluation: “It looks awesome, especially compared to what it looked like before.”