High River planting sunflowers to purify soil from flood toxins

Last summer's floods left behind a trail of destruction in High River and deposited plenty of toxins in the southern Alberta town's soil.

Nowsome people are trying to purify the groundusing sunflowers.

• EXCLUSIVE | E. coli found in High River soil months after flooding

Seeds are being delivered to every mailbox in town, all inhopes of purifying the soil using a technique called phytoremediation.

While it might sound complicated, botanists say it's really quite simple.

"Essentially what you're doing is using plants to suck up all the toxic waste from the soilinto the plant," said Marcus Samuel, a botanist with the University of Calgary.

The plants will have to be cut down and thrown away after sucking up the toxins and Samuel warns residents definitely should notbe eating the seeds.

It's also a low cost option compared to expensive soil remediation treatments. The techniquewas used successfully in New Orleans after Hurricane Katrina in 2005.

Sunflowers can absorb many different toxins and chemicals from the soil and then store those chemicals at the cellular level. Once they're absorbed, they won't leach back out again.

Not all plant species can handle absorbing all those chemicals many woulddie from the heavy metals in the soil.

But given the huge biomass and rapid growth of sunflowers, they can isolate the chemicals and continue to grow,Samuel said.

Sunflowers a 'ray of hope' for residents

CBC Newshired Benchmark Labs in September 2013 to test soil fromsix residential locations around High River.

Two of those samples came back positive for the dangerous E. coliO.157 strain, which is commonly found where there is runoff from livestock operations.

No one was infected with the bacteria but many residents were left worried about the safety of their backyards and lawns.

So far18,000 sunflower seed packets have been collected, far exceeding the 4,000 mailboxes in High River. And organizersplan to mail some out to other flood-affected communities next week.

The project is being co-ordinated out of the High River United Church.

"I mean, they rejuvenate the soil but also it's the brightness of them," said church ministerSusan Lukey. "It's just like a ray of hope."

The process will take some time and residents mighthave to keep planting the sunflowers over several seasons.

Residents in Black Diamond, Turner Valley, Canmore and Calgary will be getting their own little packets of sunshine soon.