Q: I frequently visit the free DeKalb county compost/mulch pile on Memorial Drive. After spreading two truck loads on my dormant vegetable garden, I‘m worried that the compost might have high levels of herbicides or pesticides.
A: I took a very informative tour of the DeKalb County composting operation on your behalf recently and I came away very impressed! Charles Gill, Superintendent of Processing and Disposal, estimates that they receive less than 1 percent of grass clippings (by volume) each year. He took me to the huge “incoming” pile, which was composed mostly of leaves, brush and logs. Even if some pesticides got into the debris, the material is piled in long windrows and turned regularly for several months. This accelerates the breakdown of lawn chemicals.
According to Billy Malone, Assistant Director of the DeKalb Sanitation Department, they collect more than one hundred thousand tons of landscape debris each year. 214,00 cubic yards is composted for several months and then returned to distribution sites for the public to use in their landscapes. 409,000 cubic yards are shredded and used for mulch.
I suppose DeKalb compost could have an occasional bird or dog dropping in it but not human waste. Composting rules for Georgia strictly regulate the use and disposal of sewage. The county uses other means getting rid of their sludge.
I would feel comfortable using the county compost on a vegetable garden…. but you can perform an easy test to make sure it is non-toxic. Simply mix the compost 1:1 with potting soil and plant bean seeds or a seedling tomato in it. If the plants seem to grow normally, I think you can conclude the compost is safe for general use.