The confusion over San Francisco’s “organic” sludge isn’t unique. The USDA doesn’t regulate which fertilizers can be labeled as organic, allowing anyone to use the term. But Cummins says it’s particularly misleading to apply the “organic” term to treated sewage sludge, which has been known to contain high levels of pollutants such PFOAs and flame retardants. Mother Jones‘ report that President Obama’s “organic” White House vegetable garden was planted on sludge-treated land led to considerable outcry last year. Read more.