Richey Piiparinen | 05/12/10 @ 1:00pm
What if in our attempts to Re-Imagine we find that some of the realities behind our visions won't follow? Do we fight through it? Or will we fall back into the resting state of what is a Cleveland ho hum?
These were the thoughts on a lot of folks' minds as they came to an NPI-sponsored public workshop to hear the good news of phytoremediation from Steve Rock, an Environmental Engineer for the Remediation and Contamination Branch of the EPA. Instead, what was given was a dose of reality. "Phytoextraction is a good idea," Rock would go on, discussing the process by which plants remove metals like lead from soil, "but we are not really good yet, and I wouldn't recommend it."
Now, there are rather amazing vegetative miracle-makers out there that are hyperaccumulators, like the Sebertia acuminata tree existing in New Caledonia that uptakes so much nickel it drips blue sap, but these are rare. And as for lead: such miracle-makers don't exist, according to Rock. "There are hundreds of thousands of plants we haven't tried yet," Rock would say, perhaps addressing those in the crowd envisioning a city fielded with sunflowers that'd be eating up yesteryear's fallout, "but from what we tested, lead and other metals just aren't easily picked up."
He would know, as they have been trying. In fact, Rock went on to discuss how the EPA does have chemicals that can make lead more mobile in the dirt, in effect turning a normal accumulating plant into a hyperaccumulator-but there are major drawbacks. The foremost of these is the fact that though making metals move in the soil will increase their uptake through a plant's root, the majority of the lead escapes elsewhere, like into the water table. "Not good," Rock would state.
Still, while the rather sexy process of phytoextraction via pretty plants may not yet-if ever-be up to speed, there was good news for the green thumbs in the room, many of whom were Re-Imagining grantees. "Now what I can tell you," Rock would go on, "is that the benefits of being outside, getting exercise, and growing your food will outweigh any potential dangers of working in lead-contaminated soil." But, there were basic precautionary measures that must be followed according to Rock, with a shift in focus from phytoextraction to a process called phytostabilization leading the way.
In short, phytostabilization means to weigh the lead down, and don't eat it. In fact, Rock would state there is a better chance of contamination from ingesting dirt on your hands than from eating food from the soil. (That said, Rock still suggests calling the OSU Extension to get the soil tested to make sure the lead levels aren't exorbitantly high, and to also scrub and peel whatever root vegetables are being grown.) Steps to phytostabilization are simple, and suggestions Rock gave include:
- Get the pH levels in your soil tested. Soil should be in the 6 to 10 range. Any levels lower than that increase the mobility of the lead in the soil.
- Add a soluble rock phosphate to the soil. Phosphates do wonders in that it binds lead together, forming it into crystals that make it very difficult for human ingestion.
- Lastly, cover the soil. Where vegetation isn't, mulch it or cover it with wood chips.
Of course, stabilization is not quite the buzz that'll be sustaining Cleveland's sustainability movement. Yet it is simply a reiteration of what we already know: that there are no quick fixes here. Neither in our attempts to change the way we see and live in our city, nor in the manner of remediating those toxins that'd been used to build the city on top of our hurt environment. Still, stabilization is not so bad, as it beats falling further into that mental and physical decline that has dictated the way things have been done around here-up to now. So plant the pretty anyway. After all, sunflowers do at least have bioenergy capacity. And one last reminder: don't eat the dirt.