Why Bioremediation Is Scarce in Urban Gardens

Bioremediation techniques must face a series of hurdles before being accepted as feasible, large-scale soil contamination solutions.

| July 2013

Earth Repair

"Earth Repair," by Leila Darwish, is essential reading for anyone who wishes to transform environmental despair into constructive action.

Cover Courtesy New Society Publishers

Packed with valuable, firsthand information from visionaries in the field, Earth Repair (New Society Publisher, 2013), by Leila Darwish, empowers communities and individuals to take action and heal contaminated and damaged land. Encompassing everything from remediating and regenerating abandoned city lots for urban farmers and gardeners, to recovering from environmental disasters and industrial catastrophes such as oil spills and nuclear fallout, this fertile toolbox is essential reading for anyone who wishes to transform environmental despair into constructive action. The following excerpt comes from chapter 2, “Earth Repair and Grassroots Bioremediation.” 

You can purchase this book from the Utne store: Earth Repair. 

The urban gardener is in regular physical contact with soil, breathing its dust and eating foods grown from it. Few others have such an intimate relationship with city soils, a resource that is seen by most others as something that only serves as a foundation for buildings and roads. Logically then, gardeners are concerned with soil contamination issues and are looking for simple and low-cost means to address them.

For a number of years now, urban gardeners and their supporting organizations have been aware of the concept of bioremediation. Bioremediation’s use of naturally occurring organisms, apparent affordability and minimal disturbance to soils all add to its attractiveness. The idea of partnering with life-forms such as bacteria, plants, worms and fungi (all of whom gardeners are already familiar with) greatly adds to its appeal. Numerous scientific studies have been conducted that support bioremediation’s effectiveness — there’s no question that given the right circumstances, these organisms have the potential to degrade, immobilize or sequester a variety of contaminants. Bioremediation would appear to be an ideal and elegant solution to issues of soil toxicity. Why then, have bioremediation techniques not yet been put into use broadly as a means to remediate contaminated soils in urban gardens? Why are we not seeing citizen groups applying the tools of bioremediation and publishing their results?

These are questions that I have been asking for a number of years in my work designing ecologically and socially regenerative systems in urban environments. In 2004, the Rhizome Collective, an organization that I co-founded in Austin, Texas, received a $200,000 grant from the US Environmental Protection Agency to clean up a brownfield site located in the city. This cleanup primarily involved removal of tons of trash and debris — a twisted mountain of concrete, rebar, wood scraps, tires and carpet scraps — from a former illegal dumping site. Although levels of organic and heavy metal pollutants on the site met residential standards, concerns remained about the safety of gardening there, post-cleanup.

Unfortunately, funding in the grant would not cover the cost of soil remediation. Shortly afterwards, I was part of an effort to establish a community-based bioremediation plan in post-Katrina New Orleans to help address residual hydrocarbon contamination left behind from the storm. Compost teas were applied to areas known to be affected by pollutants. While the program received donations of services from soil testing labs, the funds were insufficient to carry out a properly managed remediation program on the scale that was necessary.

david wechsler
8/12/2013 1:29:46 PM

This is a topic I have become very interested in over the last 4 years in sync with my interests in electro-horticulture (the science of improving plant growth using electricity). I think this is a big issue - first, when digging out my home garden I found old home & car parts in there - so it made me think - how was the land that I reside on used historically through many generations of owners? Were they safe and ecologically minded? In this case, apparently not! Also, I keep thinking of the other case where regions afflicted by disasters like flooding - most people are probably happy to eventually recover their lives, but I'm not sure they think about the implications of rising floodwaters - the spread of toxic chemicals from machine shops, cars, etc. ----- Anyhow, There are a number of good resources out there for those interested in learning more: Look at the EPA guide to bioremediation - http://www.clu-in.org/download/citizens/a_citizens_guide_to_bioremediation.pdf and phytoremediation - http://www.clu-in.org/download/citizens/a_citizens_guide_to_phytoremediation.pdf and lastly, there is a great Field Guide: http://urbanomnibus.net/2010/11/from-brownfields-to-greenfields-a-field-guide-to-phytoremediation/. One more thing - these technologies can also be sped up using biostimulation and electro-horticulture technologies, so IMHO, the drawbacks of using phytoremediation can be averted.