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How Safe Is Your Soil?

Urban farming has become hugely popular in the East Bay, but lead and other heavy metals in the soil pose potential health risks. Meanwhile, there's little consensus on what to do about it.



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No matter how Oakland and Berkeley approach their new regulations, carting away contaminated soil to a hazardous waste dump doesn't appear to be a viable option. That's why the proponents of the Community Crossroads Garden are so miffed that that's the solution they were offered. Beyond being costly and impractical, it merely moves the problem somewhere else. The same is true when using plants like sunflowers and bamboo to absorb lead and other heavy metals, which must be similarly disposed of. But there's another large-scale solution that may hold serious promise.

In June, Steve Calanog of the EPA began demonstrating a treatment in West Oakland's South Prescott neighborhood that uses ground-up fish bones to bind lead in soil and create stable compounds that are harmless to humans. Once mixed with the soil, decomposing bone fragments deposit phosphates that move through the soil and encapsulate tiny particles of lead. A six-inch layer of clean soil is poured over the top, leaving the dirt safe to plant in. An entire yard can be remedied with one treatment, which takes a few weeks to run its course. The EPA's two-year project here marks the first time that the approach, already proven at military and mine sites over the last fifteen years, is being employed in a residential setting.

The need for a full arsenal of solutions will only grow as demand for urban farmland increases, whether it's in backyards, abandoned lots, or city parks. While the 39th Street neighbors don't currently have plans to resurrect their garden, another neighborhood organization is looking to site a smaller garden at one of two local parks, including one just a couple blocks away.

Myriad organizations geared toward food justice and urban farming are based in Oakland alone: Ghost Town Farms, City Slicker Farms, East Bay Urban Agriculture Alliance, Oakland Food Policy Council, Institute of Urban Homesteading, Phat Beets Produce, People's Grocery, Oakland Based Urban Gardens, and Bay Localize, to name a few.

In Berkeley, groups like the Berkeley Community Gardening Collective and Urban Adamah are preaching the same gospel. Yet there's only so much land to go around, and most of it requires some level of remediation — or avoidance.

In the end, the soil contamination issue comes down to that: Fix it with compost, fish bones, or other bioremediation methods, or leave it well enough alone by mulching and planting vegetables in a raised bed. In the middle of a city, gardeners still have to deal with the daily deposition of heavy metals through particulate matter in the air — so washing before eating remains imperative.

No matter what urban farmers have to do to get it, they're better off enjoying their own fruits and vegetables than those bought at a grocery store, said Rudy Blume, founder of the Oakland-based Institute of Urban Homesteading and co-author of the book Urban Homesteading. In fact, she said, she can hardly believe that people are so worried about lead contamination when, elsewhere, farmers are spraying their crops with pesticides and herbicides. "I just feel like the food that I grow in my yard is going to be so much healthier than conventional agriculture," she said.

And she has a point. But you know what they say about an ounce of prevention.

Want to Safely Start a Garden?

1. Test your soil.
2. Based on the results, perform appropriate remediation. (Options: amend native soil with compost, plant in raised bed with root barrier, and/or mulch yard to reduce risk of exposure.)
3. If desired, test your produce.
4. Ensure that kids and pets do not play in or ingest leaded soil.
5. Wash your hands after handling leaded soil and avoid inhaling dust.
6. Always wash or peel produce before eating.

Who Can Help?

Alameda County Lead Poisoning Prevention Program:
Alameda County Master Gardeners:
UC Davis Analytical Lab:
UMass Soil and Plant Tissue Testing Laboratory:
Bay Localize:
Berkeley Community Gardening Collaborative:
City Slicker Farms:
East Bay Urban Agriculture Alliance: Institute of Urban Homesteading: Oakland Based Urban Gardens:
Oakland Food Policy Council:

Clarification: The original version of this story stated that Alameda County offers free soil testing to residents, however, the county provides garden soil lead test kits only to owners of pre-1978 residential properties in the cities of Alameda, Berkeley, Emeryville, and Oakland. This version has been updated to reflect the change.