When First Lady Michelle Obama planted an organic vegetable garden on the White House lawn in March 2009, she hoped to both set an example of healthy eating and to grow tasty edibles for her daughters and husband. But Michelle's organic dream has been dashed by a nasty toxic legacy lurking in the soils of 1600 Pennsylvania Avenue. It turns out that a previous Presidential gardening team had used sewage sludge for fertilizer.
This is a fairly common practice with one huge problem. Sewage sludge tends to be laced with anything that people pour down the drain and often contains heavy metals. Not surprisingly, the National Park Service tested the dirt beneath Michelle's garden and found the plot has highly elevated levels of lead averaging 93 parts per million. That's below the 400 ppm that the Environmental Protection Agency says is a threat to human health. But I'd wager that Sasha, Malia and Barack won't be getting arugula or tomatoes from this garden any time soon.
The likely source of the toxic sludge that has ruined Michelle's garden? The Clinton White House apparently used a sludge-based product to fertilize the lawn during the 1990s! Aside from casting a shadow on the first White House vegetable garden since Eleanor Roosevelt resided there, the sludge ensures that Michelle's garden will never attain organic status. Organic certification processes strictly prohibit the use of sludge as a fertilizer substitute.
The White House has sought to downplay the issue, and a number of experts have pointed out that 93 ppm of sludge in soil is somewhat normal for older urban locales. However, the EPA recommends not growing food in soil that has 100 ppm. Several major food producers, including H.J. Heinz and Del Monte, won't accept produce grown in sludge. That's despite decades of U.S. government efforts to encourage farmers to use solid sewage wastes in lieu of traditional fertilizer products.