Urban Farming – A Practical Guide for Interim Use

Display from City Slickers urban farm in Oakland.

Under no circumstances should a project proponent take any action that would put the health of urban farmers or the consumers of their produce at risk.

By Markus B. Niebanck
Brownfield Renewal
Markus B. Niebanck, PG is an environmental consultant and Brownfield practitioner working out of Oakland, California.

Excerpt:

Protective alternatives were considered and implemented, and included:

Excavation of shallow soil from property line to property line and the transportation of excavated material to an off-property facility (landfill) for disposal. This is the alternative often recommended by service providers or regulatory agencies that rely on the common residential-standard cookbook approach to site preparation. This approach is often prohibitively expensive.

Modification of “input parameters” for risk models, such that realistic means and durations of exposure are established. Often the simple rationalizing of the evaluative method brings substantial and demonstrably acceptable change to a contaminant’s risk profile.

Grading of shallowest soil and construction of an on-property feature for containment. The soil stored in the features would be disposed of at a later date when the property is redeveloped for its next use. The graded area is filled with crushed rock or decomposed granite to prevent contact by users with underlying material (a raised-bed planting scenario).

Amendment of shallow soil for stabilization of contaminants. Viable for only certain contaminants, the appropriateness of this approach is sometimes more difficult to effectively communicate to neighbors and site users, as the contaminant is not actually removed from the property (or secured in a site feature).

Read the complete article here.