Representatives from the Environmental Protection Agency (E.P.A.), URS, and City of Chicago outlined how to safely farm an urban garden on top of a contaminated site at a national conference on brownfields. As Amy Yersavich, Ohio E.P.A. explained, "urban gardens aren't going to come and go. They are here to stay so we need to focus on making them safe." In fact, in many cities like Detroit, San Francisco, and New York City, urban gardening on all types of sites is "moving forward with leaps and bounds." She has noticed that even Rustbelt states are transforming their brownfields into urban gardens. "Everyone wants fresh, healthy, local foods." 

Urban agriculture is the "production, distribution, marketing, and disposal of food and other products in the centers and edges of metropolitan areas." This budding field deals with neighborhood mobilization, land and water use, pollution, health, and other issues. Programs can be private or public, volunteer-led, linked with food banks, or constructed by a landscape architect or horticultural expert. Even some park departments are starting urban farming programs.

For residential urban gardens, it's important to look at whether the backyard used to be part of an industrial brownfield site. "A backyard could have been a brownfield in the past, or nearby some defunct facility." Yersavich said residential gardens may have also been sites of historic "burn pits," used early in the century to burn garbage. In addition, lead paint flakes can spread to yards.

In a test of 30-35 new pilot urban gardening sites in Cleveland, Yersavich said the E.P.A. was most concerned about testing for metals (arsenic, lead); polycyclic aromatic hydrocarbons (the result of incomplete combustion in burn pits); volatile organic compounds (VOCs); PCBs, and other metals, herbicides, pesticides, and dioxins. Furthermore, there are often site-specific issues.

She said in most sites tested most plants had "limited uptake of contaminants" but more research is needed. She said if someone is concerned about what's in the soil, they should avoid planting leafy green vegetables, carrots, and other root vegetables. Beyond the food that is consumed from these sites though, the E.P.A. is concerned about the potential health impacts for someone touching, inhaling, and accidentally eating contaminated soils every day. "We are creating stringent soil standards to determine acceptable exposure rates." While these standards may end up "ruling out many potential brownfield sites," at least gardeners will be kept safe.

Amy Steigerwald-Dick added that clean-up standards may need to be adopted for different scenarios and uses of urban gardens. A standard's level of stringency will depend on how many days a year a gardener is expected to be on a site. Residential and commercial land use standards may be different. There may also be distinct standards for recreational or green space use. Parks and playgrounds will be treated the same as residential areas, "areas of heavy use."

She said urban garden owners can do a few things. First, they should test the soils in a variety of places for the metals and other compounds mentioned. Second, if they discover the site "exceeds toxic levels," they should "cover a site with clay soil, remove localized hot spots, use raised beds with clean soils, or add vertical or hydroponic gardens." Gardeners can also go up and add a farm on their roof. Any of these solutions can "be extremely productive."

Despite the fact that national rules haven't been worked out yet, Kenneth Kastman, URS, said a number of cities are moving forward with urban gardening ordinances. San Francisco, Cleveland, Detroit, Denver, New York City, Philadelphia, Portland, Seattle have or are in the process of releasing new codes. In Detroit, the city is approaching vacant landlords and asking them to sell their properties back to the city at reduced rates. The city is then turning these over to urban farmers if they commit to "making tangible benefits" to the property. If they fail to live up to their end of the bargain, the property goes back to the city. Detroit has also significantly reducing permitting fees for community gardens.

San Francisco allows residential sales of homegrown produce, which most cities don't. However, urban gardeners can't create storefronts or any permanent retail structure, only a temporary table. Also, foods can't be baked or "value-added." Plain fences (no chain link ones) are a must. No mechanized equipment can be used. In contrast, Madiso is "totally laid back and allows for basically everything."

In Chicago, Zachary Clayton, Chicago city's government, said restaurants have been the driving force. "They want sustainable, local produce." Currently, there's nothing official on the books in Chicago. "The zoning code currently doesn't even allow urban farming." However, the city is in the process of revising and creating some very progressive codes. Community gardens can be a maximum of 18,750 square feet. Incidental sales will be allowed. Commercial gardens will need parking, screening, and retail areas. The city has also made commercial and residential composting acceptable. As with any big change, "some residents were big advocates and others were opposed. That's just Chicago."

Learn more at the E.P.A. urban agriculture Web site.

Image credit: Urban Farm, Detroit / Celsias