Crop of 5000 sunflowers to extract lead from soil

SUN-POWER: Dianah Mieglich, of the Targeted Lead Abatement Program, and Grant McKenzie, of the Port Pirie Regional Council, give a glimpse of the sunflower crop.
SUN-POWER: Dianah Mieglich, of the Targeted Lead Abatement Program, and Grant McKenzie, of the Port Pirie Regional Council, give a glimpse of the sunflower crop.

A triumph of industry is rising at one end of Ellen Street and at the other Mother Nature is about to improve our environment with sunflowers sucking up heavy metals.

BACKYARD BEAUTIES: Catherine Window has sunflowers growing in her backyard at Crystal Brook.

BACKYARD BEAUTIES: Catherine Window has sunflowers growing in her backyard at Crystal Brook.

The $660 million Nyrstar smelter “transformation” is on target for an opening in January next year when it is hoped there will be a “sea of yellow” beside the courthouse.

This is the site for 5000 sunflowers for which seeds have been planted on vacant land in a pioneering move to reduce lead contamination in soil.

Nyrstar and the Targeted Lead Abatement Program teamed with the Port Pirie Regional Council to begin a scientific trial using sunflowers to test the practicality of  extracting heavy metals from soil in Port Pirie using the process of phytoremediation.

Phytoremediation, the use of plants to extract, sequester and detoxify pollutants, is known to be an effective, non-intrusive, inexpensive, aesthetically pleasing, socially-accepted technology to remediate polluted soils. 

When considering the remediation of metal-polluted soil, such metal-accumulating plants offer numerous advantages over microbial processes since plants can actually extract metals from the polluted soils, rendering them clean.

The advantage of phytoremediation is that the lead gets sucked out of the soil and concentrates in the plants. 

This means that the volume of material needing to be disposed is less than one percent of the volume of the soil. Sunflowers are great for this purpose.

The site selected and made available via a licence agreement with council is a block in Main Road.

It doesn’t just lend itself as a preferred site for scientific purposes, but it will also offer a tourism opportunity. 

An elevated platform will be built so that residents and visitors alike can capture pictures of the “sea of yellow” which will come to full bloom just 70 days after seeding.  

Sunflowers are usually between 6 to 10 feet in height.

Dianah Mieglich, of the Targeted Lead Abatement Program, said the viewing platform would include signs and would be wheelchair-friendly.

“The plants will be harvested by hand and disposed of in a manner which will not allow for the re-involvement of contaminated materials and then a new crop will be planted to start the process again,” she said.

“Baseline testing of the soil has taken place and in coming months and years the community will receive updates about the practicality of the project.

“In line with tight trial standards, the land will be fenced and there will be no public access nor ability for the public to harvest the flowers.

“This just one of many projects being explored by the program in its work to address legacy lead issues after the redevelopment of the smelter and ongoing work to reduce emissions from the plant.”

Council’s development and regulation director, Grant McKenzie, said he had high hopes for the “spectacular” trial.

“If it works, it has got to be a winner,” he said. “It is a proven method, but it is the first time it has been done in Port Pirie.”

Cr Alan Zubrinich said it was an innovative, environmentally-friendly project to reduce “legacy lead”.

“It draws it out of the ground and you take it away and dispose of the sunflowers,” he said. “It is a wonderful opportunity.”