Q and A: Keep Sludge Off Your Garden

Q. The Green Guide article "Make Compost, Not Waste" (6/1/96) refers to 'biosolid sludge.' Food & Water Journal warns that the 'sludge' industry is fiercely trying to promote it as natural and organic. Please investigate. --Grace Sapia, IL

A. Biosolid sludge, or treated sewage, is taken from municipal solid wastewater treatment plants and increasingly recycled as compost, sold for use on gardens and crops. Unfortunately, in addition to bodily wastes, sewage often contains industrial discharges, including toxins like arsenic, cadmium, chromium, dioxins and PCBs. An EPA pamphlet states, "The biosolids now being generated are for the most part low in pollutants, rich in nutrients and organic matter..." If it meets EPA requirements, does that mean that it's safe? Not necessarily, according to Ellen Z. Harrison, director of the Waste Management Institute at Cornell University. "One clear recommendation from our soils department is, do not use sewage sludge on home gardens," Harrison says. She cites a concern about, among other things, the amount of toxins ingested by children in the soil they get on their hands.

Companies are not required to label their products as sludge-based, so consumers should ask what's in compost before they buy. Some brand names that use biosolids include Milorganite, Nitrohumus, Topper, Gro-Mulch, Compro and Earthgro. "Another concern for the home gardener--cadmium is absorbed by leafy vegetables," Harrison says.

+ Call for the free EPA pamphlet "Biosolids Recycling," which discusses the risks and uses of biosolids; including use on agricultural land, 202/260-7786.

+ Food & Water Journal, 800/EAT-SAFE.

+ Toxic Sludge is Good For You (Common Courage Press, 1995) by John Stauber and Sheldon Rampton, the source for the Food & Water Journal article; $16.95 plus $3 shipping; 800/497-3207.

+ Contact Lauri Wellin for sludge factsheets, Cornell University, Waste Management Institute, 100 Rice Hall, Ithaca, NY 14853, 607/255-1187, lew4@cornell.edu --MP