Refute

Meg dug up additional dirt on the sludge-infested garden...

In Obama Garden, Less Lead [NYT 8.13.09]

... While acknowledging that 93 p.p.m. was not a hazard, Mother Jones magazine’s Web site attributed the long-term use of sludge as a fertilizer on the White House lawn for the presence, not just of lead, but of many other undesirable substances like antibiotics and sleeping pills. Sludge comprises the solids in sewage that separate out during treatment. According to the magazine, sludge was used for at least a decade on the White House lawn, possibly until the late 1990s.
But Irvin Williams, who retired as head groundskeeper at the White House last year, after 59 years on the job, said sludge was used only once there, in 1985. ..