Urban contaminants must be confronted for the sake of healthy water, soil, and consumers.
In an area like ours where mills once dominated the landscape, contamination is a serious risk. Urban farmers need to consider that their products can become contaminated by root absorption or via dust in the air. Precautions must be taken and the presence of contamination may impact your entire operation. For example, perennial fruit plants in an orchard will carry a different risk than root vegetables grown in direct contact with the soil. An option may be to avoid soil contact entirely by growing hydroponically, cultivating mushrooms, or growing in raised beds. Though contamination in an urban environment may be widespread, there are still plenty of ways to make urban agriculture work.
Suppose urban farming stakeholders have a significant liability concern and all risk of contamination needs addressing. The remediation of some contaminants may be quite difficult and expensive depending on the type of contaminant. There are several possible contaminants in highly populated areas. This all depends on the previous use of the land and proximity to contaminated water ways. Some common chemicals of concern are petrochemicals, heavy metals, and polychlorinated biphenyls (PCBs). In fact, some contaminants may have been in the ground for centuries.
Remediation
Remediation efforts include scraping up, properly disposing, and replacing contaminated soil with clean soil. Other remediation may involve growing in clean soil on top of contamination via impermeable barriers such as raised beds. There are even specific species that, over time, can mend contaminated soils as well. For example mycoremediation uses mushrooms to essentially soak up contaminants. Upon harvest, the mushrooms can be collected and disposed of safely. In addition, mushrooms can be “trained” to eat and render petrochemicals into less dangerous forms.
We have also read about phytoremediation, which uses sunflowers to soak up heavy metals into their tissues. Likewise, bacteria can also be used to transform petrochemicals into harmless element compounds. Ultimately, if we do find pollutants, there are a number of routes we can take to remove them.
Brownfields
“Brownfields are properties where the expansion, redevelopment, or reuse may be complicated by the presence or potential presence of a hazardous substance, pollutant, or contaminant. Since 2000, the City of Greenville has received approximately $1.8 million from the US Environmental Protection Agency (EPA) brownfield grants.”
We were lucky to secure grant funding for our site. The grant project uses funds from the EPA to help developers understand invisible contamination risks. The grant funded a Phase I Environmental Assessment. This assessment initiates a formal reporting process conducted by an environmental engineering firm to explore the history of the land. This is done by using available databases, photographic evidence, and personal interviews. Upon completion, the stakeholders learn about potential Recognized Environmental Issues. If the report shows Recognized Environmental Issues, a Phase II Environmental Assessment may be requested. If needed, The Phase II Assessment requires additional expense as this calls for more elaborate site testing such as trenching and soil laboratory testing.
Results to be determined!